What are Cookies and What do They Serve For?

In order to carry out manual and automated testing of web software products one should be familiar with all the peculiarities of modern web technology.

One of web technology aspects is cookies. Nowadays most of web sites and web applications use them.

Everybody heard about cookies, but those who are involved in usability testing, compatibility testing, localization testing or other testing types of web software must know what they are, and for what they serve.

Cookies are text files stored on the user computer. Such files are created by the web applications with which the user interacts, they contain data allowing to identify the user and continue work with the application based on the previous interaction with it. They store history of the user work with the web application.

Cookies are utilized by browsers and the web servers, they help to direct the users to the required web pages, display the suitable data.

So, every time when a user visits a web site that utilizes cookies, special code embedded in HTML pages activates and creates or edits cookies on the user device.

Web servers need HTTP protocols for maintaining their cookies.

HTTP Protocols Can be of 2 Types:

  • Stateless. Such HTTP protocols do not track or document history of interaction with web software.
  • Stateful. They track and record history of data exchange between a web browser and web server.

Stateful HTTP protocols are used by web servers for making cookies.

These technical aspects sometimes are utilized in functional testing, performance testing, security testing, etc.