HTTP

HTTP stands for Hypertext Transfer Protocol. It is the foundation of data communication on the World Wide Web. Here’s an overview:

Basics of HTTP:

  1. Protocol: HTTP is a protocol, which means it’s a set of rules that determine how messages are formatted and transmitted over the web.
  2. Stateless: HTTP is stateless, meaning each request from a client to a server is treated as a new, standalone request with no memory of previous interactions. This led to the creation of cookies and sessions to maintain user-specific states.
  3. Connection: Typically, HTTP uses a TCP (Transmission Control Protocol) connection for communication.

Key Concepts:

  1. URL (Uniform Resource Locator): URLs are used to fetch resources. A URL like http://www.example.com/ uses HTTP to access the resource at www.example.com.
  2. Methods: HTTP defines a set of request methods that indicate desired actions on the identified resource. Some of the most common include:
  • GETRetrieve a resource.
  • POSTSubmit data to be processed to a specified resource.
  • PUTUpdate a resource.
  • DELETEDelete a resource.
  1. Status Codes: The server responds to an HTTP request with a status code. Some common ones include:
  • 200 OK: Successful request.
  • 404 Not Found: The requested resource could not be found.
  • 500 Internal Server Error: A generic error message indicating an unexpected condition.
  1. Headers: Both HTTP requests and responses contain headers that provide meta-information about the content, the client, the server, and other data.
  • For example, User-Agent header indicates which web browser is being used.
  1. Cookies: Small pieces of data stored in the user’s browser to maintain state between requests.
  2. Sessions: Server-side storage of information that persists across multiple requests.

HTTPS:

  • Stands for HTTP Secure.
  • It’s HTTP but with added security using SSL/TLS protocols.
  • Encrypts the data between the client and the server to protect against eavesdropping, tampering, and phishing attacks.

Significance:

HTTP is essential for the functioning of the web. Without it, browsers and web servers would lack a common language to communicate. While the original HTTP is less secure and subject to eavesdropping, the introduction of HTTPS added the necessary encryption to keep data secure during transit.

Key terms in plain language

Open a term for a concise explanation of language used on this page.

Cloud Computing

Computing resources—such as applications, servers, storage, or databases—delivered from remote infrastructure and scaled as requirements change.

Infrastructure as a Service (IaaS)

Cloud-based servers, storage, and networking that customers configure and manage without owning the underlying data-center hardware.

Software as a Service (SaaS)

Software accessed as an online service instead of being installed and maintained entirely on the customer’s own computers or servers.

Disaster Recovery (DRaaS)

A plan and service for restoring applications, data, and operations after an outage or disruption. DRaaS provides recovery infrastructure through a managed cloud service.

Identity and Access Management (IAM)

The systems and policies that determine who a user is, what resources they may access, and how that access is authenticated and reviewed.

API

An application programming interface is a defined way for software systems to exchange data or request functions from one another.