HTTP and REST

Largely based on a reading of HTTP: The Protocol Every Web Developer Must Know by Pavan Podila and a viewing of What Is A RESTful API? Explanation of REST & HTTP by Traversy Media.

Summary

What is a REST API?

What is an API?

Application Program Interface

This is a broad, generalized term referring to a contract provided by one piece of software sent to another piece of software. "Give me this information formatted in this way, and I'll give you this data formatted in this way."

API Analogy

In a restaurant, there is a customer at a table, a kitchen, and a waiter. In this scenario, the waiter is the API. He is formatted to take a certain order in a certain way, and then bring back a certain meal. So an API is basically a messenger or a waiter between running software.

What is REST?

Representational State Transfer

• Architecture style for designing networked applications
• Relies on a stateless, client-server protocol, almost always HTTP
• Treats server objects as resources that can be created or destroyed
• Can be used by virtually any programming language

An API is a messenger, and REST lets us use HTTP requests to format those messages. "RESTful API" refers to an API that conforms to the REST constraints.

HTTP Methods

GET

Retrieve data from a specified resource

POST

Submit data to be processed to a specified source

PUT

Update a specified resource

DELETE

Delete a specified resource

Less-common HTTP methods:

HEAD

Same as get but does not return a body

OPTIONS

Returns the supported HTTP methods

PATCH

Update partial resources

Authentication

Some API's require authentication to use their service. This could be free or paid.

Resources

Read

• http basics

Watch

• http and rest

Bookmark

• http reference
• rest reference