Application Programming Interface , a quick introduction

API is the most common buzzword in today's IT industry. While the developers and programmers have sufficient knowledge, there is an equally big chunk of IT population who is at loss of truly understanding its genesis and the jargons involved. This attempt is to simplify and gives a birds view of what actually is API, its history in brief and various forms and parts. Hope you will all find this as enjoyable as I got it while creating.

1. Application Programming Interface
(API)
An introduction
Jahangir Shaik

2. 40s & 50s
60s & 70s
90s
2000
API: Application Programming Interface (API) is a type of software interface, by which, two or more computer programs or
components communicate with each other
In 1940, British computer
scientists Maurice Wilkes & David
Wheeler developed modular
software library for EDSAC, an
early computer system. These
Library Subroutines were created
on punch paper and organized in a
filing cabinet. The cabinet also
contained catalogue of notes that
detailed on how to use subroutines.
Such catalogue today, will be called
as API
First recorded instance of
term "application program
interface" showed up at AFIPS
conference in 1968. However,
the actual term API was
introduced by C.J.Date in 1974
and became a part of the
ANSI/SPARC framework for DB
management systems
Continuing the
evolution, in 1990, the
API was defined simply
as set of services
available to a
programmer for
performing certain
tasks" by technologist
Carl Malamud
Our current API definition
stems from Roy Fielding’s
dissertation presented at UC
Irvine in 2000 that described
Representational State transfer
(REST) and discussed the idea
of “Network-based
Application Programming
Interface”
Definition & History

3. Composite API
Also known as Hybrid API;
Combines multiple data and
service APIs; Allow developers to
access multiple endpoints
simultaneously
Public/External API
These are meant for general users
and anyone from public dev
community; Have minimal
restrictions; Also known as Open
API
Private/Internal API
These are solely for consumption
within the organization and is
exposed only to internal systems;
Meant for cross functional
development activities
Partner API
These are dedicated for strategic
business partners usage; Not
available publicly and needs
special entitlement for access
API Strategies

4. REST APIRepresentational State transfer; These are Web Services API; Crucial for modern day
applications; Simpler than traditional SOAP; Most widely used
SOAP APISimple Object Access protocol; is a type of Web API; However, comes with rigid standards and in
some cases, is quite resource intensive
RPC APIRemote Procedure Call; Oldest and simplest; However, they are tightly coupled, therefore
difficult to maintain and update
gRPC APIIts a RPC variation with advanced protocol (HTTP/2); Offers better performance, faster
transmissions & efficient bandwidth usage; Supports multiple programming languages
GraphQL APINot strictly an API; Offers powerful ways to interact with data; Flexible and intuitive syntax
makes it easy to develop; Well suited for data intensive apps
Asynchronous APIAka event driven API; Provides response from source only when information is new or changed;
Good solution for always-on apps with heavy data usage
API Protocols

5. API Methods
GET MethodThis method is used to retrieve data from the server; Most commonly used
POST MethodThis method is used to send or push data to the server; this is also most commonly used
PUT MethodThis method is used to update specified source with new data by replacing the entire content
PATCH MethodSimilar to PUT method; However instead of replacing, it only updates the contents
DELETE MethodThis method is used to delete a specified resource and the content is removed entirely
API Methods are types of requests that are sent to server; In general, there are 5 types of API methods.
They are used to perform CRUD operations (Create, Read, Update and Delete)

6. Thank you !!!
Happy Reading !