When the concept of the World Wide Web came into existence more than 30 years ago, the development and introduction of a standardized information transfer protocol was soon to follow. After managing to succinctly characterize the basic relationship between clients and servers on the World Wide Web, Tim Berner-Lee developed Hypertext Transfer Protocol (HTTP) 1.0 with the goal of simplifying file transfer functionality between servers, enabling an easy index search of hypertext archives, automatically negotiating data formats, and allowing servers to refer clients to other server resources.

How are HTTP requests composed?

Simply put, an HTTP request is a message sent from a client server to a specified host on another server with the goal of retrieving or modifying that server’s resources. This request leverages URL (uniform resource locator) components to specify a scheme (i.e., HTTP or HTTPS), a host (i.e., www.cloudmersive.com), a path (which leads to specific server resources), and a query string (depending on the nature of the request).

Through an HTTP request, clients can create, read, update, or delete (CRUD) resources on a server. The specific action taken by the HTTP request is defined by the request method, which corresponds to one of the CRUD operations. The four most common HTTP request methods include (and are not limited to):

1. GET: this method retrieves data – including images, videos, documents, etc. – from the target server.
2. POST: this method provides data to the target server for processing, such as user-completed fields from an online form, search query parameters, etc.
3. PUT: this method modifies data on the server, replacing content in a specific location with the body of the request payload. This can also generate new server resources if none exist to be replaced.
4. DELETE: this method removes data from a specific location on a server.

A correctly composed HTTP request must state the method it is utilizing, and it must also contain headers to provide the server recipient with key information about the sender – such as the way in which the sender wants to communicate with the recipient. This information makes it possible for the server to respond appropriately to the request.

When request methods like POST are used, the HTTP request must also contain a message body that contains data required to interact with the server. This data can be encoded for transport, but it must be present.