Introduction to Computer, Programming languages , Networks and Internet.pptx

This the ppt presentation of the field of computer science

1. CHAPTER NO.2,3 Introduction to Computer, Introduction to Programming languages , Networks and Internet

2. Introduction to Computer

3. What is Computer A computer is an electronic device, which can input, process, and output data. OR A computer is a machine that stores data, interact with devices, and execute programs

4. Major Components of Computer 1. Input Devices ( Keyboard, Mouse, Microphone, Scanner, Web cam ) that allows you enter data and instructions into a computer. 2. Output Devices ( Printer, A Monitor, Speakers ) that conveys information to one or more people. 3. System Unit ( Motherboard ) that contains the electronic components of the computer that are used to process data. Two main components on the motherboard are the processor and memory.

5. Major Components of Computer 4. Storage Devices ( USB Flash Drives, Hard Disks, Optical Discs, and Memory Cards ) that storage holds these items permanently.USB Flash drive can hold about 4 billion characters. A Hard Disk provides much greater storage capacity than USB Flash Drive. Hard Disk hold more than 320 billion characters. Optical Discs contain CDs. DVDs, and Blu-ray Discs. CDs hold from 650 million to 1 billion characters. DVDs hold 17 billion characters. Blu-ray Discs hold from 100 billion characters. 5. Communication devices ( Modem ) that enables a computer to send and receive data, instruction, and information to and from one or more computer. Communication occurs over cables, telephone lines, cellular networks, satellites, and other transmission media.

6. Major Components of Computer 6. Memory ( Memory is any physical device capable of storing information temporary or permanently ) two type of memory RAM & ROM RAM ( Random Access Memory ) Data is also stored in memory temporarily. Data is both written to and read from memory. ROM ( Read Only Memory ) Data is also stored in memory permanently. Data is read from memory only. 7. Processor The processor, also called a CPU (central processing unit), is electronic component that interprets and carries out the basic instructions that operate the computer.

7. Five functional unit of computer Input: This is the process of entering data and program into the computer system . Control Unit(CU): The process of input, output, processing and storage is performed CU. Step by step processing of all operation inside the computer.   Arithmetic Logic Unit(ALU): The major operations performed by ALU are Addition, Subtraction, Multiplication, Division and Logic. Memory Unit: Computer is used to store data and instruction in the form of bytes. 1Byte = 8 Bits 1Kilobyte = 1024Bytes 1Megabyte = 1024 Kilobyte 1Gigabyte = 1024 Megabyte 1Terabyt = 1024 Gigabyte Output: This is process of producing results from the data for getting useful information.

8. Computer and its Categories Personal computer: A personal computer is a computer that can perform all of its input, processing, output and storage activities by itself. Personal computer contains processor, memory, input, output and storage devices. Two popular architecture of personal computers are PC and Apple. In PC used windows operating system and in Apple used Mac operating system. A small, single-user computer based on a microprocessor.

9. Computer and its Categories cont… Handheld Computers: Handheld computers or Personal Digital Assistants (PDAs) are pen-based and also battery-powered. They are small and can be carried anywhere. They use a pen like stylus and accept handwritten input directly on the screen. They are not as powerful as desktops or laptops but they are used for scheduling appointments, storing addresses and playing games. They have touch

10. Computer and its Categories cont… Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and, in general, a higher-quality monitor. The most common operating systems for workstations are UNIX and Windows NT. Used for engineering applications , desktop publishing, software development.   Minicomputer: A multi-user computer capable of supporting up to hundreds of users simultaneously.

11. Computer and its Categories cont… Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously. Uses in banking, airlines, and railways etc for their applications. Supercomputer : An extremely fast computer that can perform hundreds of millions of instructions per second. scientific simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic design.

12. Introduction Programming Languages

13. Programming Languages A set of words, symbols and codes used to write programs is called program language. Different programming languages are available for writing different types of programs. There are two types of computer programming languages: Low-level language High level language  

14. 1.Low-level language These languages are near to computer hardware and far from human languages. Computer can understand these languages easily. Writing a program in low-level languages requires a deep knowledge of the internal structure of computer hardware. Following are two low-level languages. One is Machine Language and other is Assembly Language.

15. Machine Language A type of language in which instruction are written in binary form is called machine language. It is the only language that is directly understood by the computer. Program written in machine language can be executed very fast by the computer. Programs written in machine language are machine-dependent. Every computer has its own machine language. Machine language is also known as first generation language.

16. Assembly Language Assembly language is a low-level language. It is one step higher than machine language. Assembly language is also called symbolic language and second generation languages. Like machine language s, assembly languages are machine –dependent.

17. 2.High level language A type of language that is close to human languages is called high level language. High-level languages are easy to understand. Instructions of these languages are written in English-like words such as input and print etc. Procedural language Object- Oriented language Non-Procedural language

18. Procedural language Procedural languages are also known as third-generation languages or 3GL . Third-generation languages are also considered “procedural” because the programmer has to detail a logical procedure that solves the problem at hand. Some common procedural languages include FORTRAN ( FORmula TRANslation ), COBOL (Common Business Oriented Language), and BASIC (Beginners All-purpose Symbolic Instruction Code).

19. Procedural language FIGURE The instruction, Add 2 and 5 and assign the result to variable y” written in different programming languages” Programming Languages Code FORTRAN y=2+5 COBOL add 2, 5 giving y BASIC let y=2+5;

20. Object- Oriented Language OOP is a technique in which programs are written on the basis of objects. An object is a collection of data and functions. Object may represent a person, thing or place in real world.OOP programs are easier to learn and modify. C++ and Java are popular object-oriented languages. C++ C++ is an OOP language. It was developed in 1980 at Bell Laboratories. It is an improved version of C language. It provides the facility of working with objects and classes. It is very powerful language.

21. Non-Procedural language Non-Procedural languages are also known as fourth-generation languages or 4GL . Non-Procedural languages, user only needs to tells the computer” what to do” not” how to do”. Non-Procedural languages are that they can be used by non-technical user to perform a specific task. Used for database application and report generation. SQL (Structured Query Language): Used for database application. RPG (Report Program Generator): Used for report generation.

22. Types of Codes There are two types of codes that are as follows. Source Code: Source code is a computer program written in high-level programming language like C,C++,Visual Basic or java. Object Code: Object code is the program that is translated by a language processor. It is also called machine code. Computer understands object code directly.

23. Language Processor   Computer understands only machine language. A program written in high-level or assembly language cannot be run on a computer directly. It must be converted into machine language before execution. Language processor or translator is software that converts these programs into machine language.

24. Different types of Language Processor Compiler Interpreter Assembler

25. Compiler A compiler is a program that converts the instruction of a high level language into machine language as a whole. A program written in high-level language is called source program . Compiler converts source program into machine code known as object program. The compiler checks each statement in the source program and generates machine instructions. Compiler also checks syntax errors in the program. A source program containing an error cannot be compiled.

26. Interpreter An interpreter is a program that converts one statement of a program at one time. It executes this statement before translating the next statement of the source program. If there is an error in the statements, the interpreter stops working and displays an errors message.  

27. Assembler An assembler is translating program that translates the instruction of a assembly language into machine language.

28. Difference between Compiler and Interpreter COMPILER INTERPRETER 1 .Compiler converts a program into machine code as a whole 1. Interpreter converts a program into machine code statement by statement. 2 . Compiler create object code file. 2 . Interpreter does not create object code file. 3 . Program execution is fast. 3 . Program execution is slow. 4 . Compiler converts high level program that can be executed many times. 4 . Interpreter converts high level program that can be executed one times.

29. Network Basics And Internet

30. Network: A group of computers and other devices connected together is called a Network . Networking: The concept of connected computers sharing resources is called Networking . Computer Network: “An interconnected collection of computers that are capable of exchanging information” Two computers are said to be interconnected if they are able to exchange information. The most elementary network consists of two computers communicating over a cable.

31. What computers can do in a network Computers can communicate with each other in a network. They can send and receive data from each other when they are in a network So, it's all about sharing resources

32. Uses of computer networks Computer Networks are everywhere Email World Wide Web, Video Conferencing File Transfer Remote control of machines Hacking Banking Internet telephone

33. Why Do We Need Computer Networks We need computer networks for Sharing of resources Sharing of data Sharing of ideas

34. Network Building Blocks Nodes Hosts: general-purpose computers Switches: typically special-purpose hardware Routers : connecting networks Links: Copper wire with electronic signaling Glass fiber with optical signaling Wireless with electromagnetic (radio, infrared, microwave) signaling

35. Classification of Computer Networks Computer networks are classified by many factors: Size LAN WAN MAN PAN(personal area network)

36. Classification of Computer Networks Connectivity Point-to-Point Broadcast Mobility Fixed Mobile Signal Baseband (low cast & speed, Mostly for LAN ,digital & analog signals ) Broadband (high speed gigabit)

37. Roles of a computer in a Network   Server: They provide network resources. Client: They use but not provide network resources. Peer: They both use and provide network resources.

38. Network Architectures Server based Networks Server based networks are defined by the presence of servers on the network and are responsible for security and administration. All the resources are with server. Clients request services, such as file storage and printing and servers deliver them. Server computers typically are more powerful than client computers.

39. Server based Networks

40. Server based Networks Advantages Security Centralized control Central file storage Central backup Share expensive equipment Easy manageability

41. Server based Networks Disadvantages Expensive dedicated hardware Network OS and software are expensive Network administration required

42. Peer networks   Peer networks are defined by the lack of central control over the network There are no servers in peer networks Peer networks are organized into workgroups These are used for small networks

43. Peer networks Advantages No extra investment in hardware and software Easy setup, Low cost No network administrator required Ability of user to control sharing

44. Peer networks Disadvantages Additional loads on computer because of resource sharing Lack of central organization No central point for file storage Weak and intrusive security Each user must administrate its own computer

45. Hybrid networks Hybrid network is a combination of server based network and peer based network. Advantages : The advantages of server based networking as well as of peer based networking Ability of users and network administrator to control security based on the importance of the shared resource Disadvantages : They share the disadvantages of server based as well as peer based networking

46. Types of Networks LAN(Local Area Networking) WLAN(Wireless Local Area Networks) WAN(Wide Area Networks) MAN(Metropolitan Area Networks) CAN(Campus Area Networks) SAN(Storage or System Area Network)

47. LAN (Local Area Network) Local Area Network is used primarily in small areas such as schools, hospitals and office buildings. Local Area Network, is one of the older types of networks. TCP/IP is used as the method of communication between computers in Local Area Network. Due to its small size, it is possible for one person to administrate a Local Area Network. Local Area Networks are viable to quick change, using a  bus network topology  that allows for easy access to the Local Area Network.

48. WLAN (Wireless Local Area Networks) Wireless Local Area Networks are much like LAN networks, except they do not require network cables to connect each other. Radio and infrared signals are used to communicate between machines whilst using a wireless local area network. Wireless Local Area Networks allow for small amounts of mobility whilst being connected to the internet. Wireless Local Area Networks work according to the IEEE 802.11 standards. Wireless Area Networks are commonly seen being used by a  WiFi internet connection . Wireless LAN connections offer a surprising amount of mobility for users with laptops and smart phones while being able to stay connected to the internet by different  networking topology .

49. WAN (Wide Area Networks) Wide Area Networks are used to connect server machines and computers across continents are countries for constant information updates. Wide Area Networks, are used across the globe, many networks connect with one another across continents to create one giant Wide Area Network. Wide Area Networks use optic fiber as their communication medium. The largest example of a Wide Area Network is the internet itself, which connects all users to the information and data that is available on the internet.

50. MAN (Metropolitan Area Networks) Metropolitan Area Networks are not commonly used these days, they are used to create communication between systems in an entire city. Hence a Metropolitan Area Network area falls between the sizes Local Area Networks, and Wide Area Networks. Metropolitan Area Networks are used by city specific businesses such as the New York Times in the state of New York.

51. CAN (Campus Area Networks) Campus Area Networks are usually a connection of many small LAN networks which are often used on university campuses and office buildings. Campus Area Networks allow for easy file sharing between different departments as all the files are usually shared on the server machines of each LAN network. This type of network offers a lot of simplicity in the transfer and downloading of files.

52. SAN (Storage Area Network) Storage Area Networks are primarily used as information databases. They are not usually used by large organizations  or similar entities. They are specifically used for the storage of information, and easy retrieval of specific pieces of data whenever required. Storage Area Networks are usually used by websites which offer downloading services.

53. SAN (System Area Network)   System Area Networks are speed oriented networks which provide high speed internet connections to a cluster of computers. These are primarily used for server purposes, and allow other computers to connect to these System Area Networks. Permission to different access points are given according to what status a system is on the System Area Network, such as administrators or simple users.

54. THE INTERNET The largest network of networks in the world. The internet is the network of networks around the world. It is a global network of computers. its is a made up of thousands of smaller, national, regional, governmental, academic and commercial networks. A large number of books, newspapers, magazines and other types of materials are available in electronic form on the internet. we can find information about almost anything in the world and can access latest information or news on any topic. It means that internet is an ocean of knowledge.

55. HOW THE INTERNET WORKS Definitions Uniform Resource Locator (URL) Hypertext Transfer Protocol (HTTP) Domain Name Hypertext Markup Language (HTML) Top Level Domain (TLD)

56. HOW THE INTERNET WORKS …cont.

57. HOW THE INTERNET WORKS …cont. .com in our example, is called the top-level domain. TLD often indicates the type of entity that registered the domain name, such as commercial organization, nonprofit organization, or individual.

58. INTERNET DOMAINS NAMES AND IP NUMBERS IP Number: is 32 bit numeric address, presented in four parts separated by periods, such 146.186.87.220 and each of the parts may be a number between 1 and 254. Domain Naming System (DNS) DNA servers are maintained by internet service providers( isps ) and other organizations. A domain name is assigned to each IP address Domain names are registered by one of a group of companies authorized to assign unique names

59. INTERNET DOMAINS…cont.

60. STATIC AND DYNAMIC IP NUMBERS Static IP Number When connected Servers and many other computers and devices are assigned a permanent IP number, called a Static IP Number. Dynamic IP Number A computer connected to the internet intermittently may be assigned a temporary IP number for the duration of its connection only. Such a number is called a dynamic IP number.

61. COMMON INTERNET APPLICATIONS E-MAIL FILE TRANSFER NEWSGROUPS AND BLOGS INTERNET TELEPHONING(SKYPE) WEB BROWSERS SEARCH ENGINES

62. Intranet: An organization network, through which the files and messages can be exchanged among the users of the organization only. Extranet: An extranet is a network of multiple intranets. Its means that intranets of different companies are connected together for sharing information among them.

63. Internet ,intranet and Extranet

64. Services Provided by Internet World Wide Web News Groups File Transfer Protocol (FTP) Web TV/Radio Chatting Electronic Mail

65. Search Engines Popular Search Engines on the Internet. Google Yahoo Ask Live Search MSN Yahoo!

66. Search Engines example

67. Terminologies and Tools Used for Internet Server Client Hosts Web Browser Internet Protocols Web Pages Website Home Pages HTML URL Address

68. Terminologies and Tools Used for Internet Server A server stored web pages or files and sends information over the Internet in response to request from the web browser. Client User gets information from the server as well as sends information to other users through server is called C lient. Hosts The computers that are connected to the internet and exchange information between users on the Internet are called H osts.

69. Terminologies and Tools Used for Internet Web Browser A web Browser is a software that allows the Internet user to access and view web pages on the Internet. Internet Protocols IP are set of defined rules and procedures used for communication through which Internet Users exchange information on the Network e.g. TCP/IP,FTP,HTTP. Web Page The documents on the Web are called Web Pages e.g. simple text, images.

70. Terminologies and Tools Used for Internet Website A collection of related Web Pages stored on a Web Server is called Website.  Home Page The main page or title page of a website that contains the links of other web pages is referred to as home page. HTML HTML is stands for Hyper Texts Markup Language. It is a fundamental Language, which is used to design web pages.

71. Terminologies and Tools Used for Internet URL /Address Bar URL stands for Uniform Resource Locator. It is a unique address of web pages or any other file on the Internet. http://www.google.com/myfolder/myfile.htm http( Hypertext Transfer Protocol ) is a protocol used to encrypt the data being transmitted. www.google.com is a Domain Name. my folder is name of folder . myfile.htm is name of file of html .