Explain State and Stateless Web Applications

When a Web Server receives a web page request (HTTP GET request) from a web browser, the Web Server process the HTTP request and send a response back to the web browser and the browser process the response and shows the web page in the browser. After sent back the response to the web browser, the web server releases or disconnect all the resources which were involved with the request. So, the web server and web browser doesn't have retain any open connection. This type of web applications are calling stateless web applications (Stateless Environment) (Figure 1). Many of the legacy web applications were stateless.

Figure 1 - Stateless Environment

However, modern web applications maintain states (Figure 2), that means they remembering what they did last time by implement various state management techniques, such as Cookies, Cache, QueryString, ViewState, Sessions, Application state, Static variables and profiles.

Figure 2 - State Environment

For more information about state management, click on What is State Management in Asp.Net?