• HTTP is the foundation of the world wide web.

• The main objective of HTTP is to load webpages using hyperlinks.

Origin of HTTP

• Developed by Tim Berners-Lee and his team between 1989-91.

• After that, HTTP has gone through many changes that have helped maintain its simplicity while shaping its flexibility.

• Versions of HTTP: HTTP/0.9, HTTP/1.0, HTTP/1.1(used for 15 years), HTTP/2, HTTP/3.

• whenever the web browser requests any request say image, video, etc it is called a request and when a message is sent to the server as an answer is called a response.

• HTTP can also be used to fetch parts of documents to update Web pages on demand.

Basic aspects of HTTP

• A typical flow over HTTP involves a client machine requesting a server, which then sends a response message.

• HTTP is simple and human-readable as its messages can be read and understood by humans, easier debugging for developers.

• HTTP is a connectionless protocol. when the HTTP client initiates a request and waits for a response from the server.

• As the server receives the request, the server process the request and sends back the response to the HTTP client after which the client disconnects the connection.

• In other words, HTTP is connectionless except during receiving a request and during receiving a response time only.

• HTTP is stateless as there is no link between two requests being successively carried out on the same connection.

Methods

1. GET: a ‘GET’ request expects information back in return (usually in the form of a website).

   

   -> The request method tells us what to do.

   -> URI(uniform resource locator) which shows readable characters and a way to locate the resource.

2. POST: a 'POST' request typically indicates that the client is submitting information to the web server (such as form information, e.g. a submitted username and password).

   

APIs based on HTTP

• The most commonly used API based on HTTP is the XMLHttpRequest API, which can be used to exchange data between a user agent and a server.

• The modern Fetch_API provides the same features with a more powerful and flexible feature set.

Therefore, we can say that HTTP is an extensible protocol that is easy to use. The client-server structure, combined with the ability to add headers, allows HTTP to advance along with the extended capabilities of the Web.