State management is a technique that is used to manage a state of an object on different request. It is very important to manage state in any web application. There are two types of state management systems in ASP.NET.

Client side state management
Server side state management

In ASP.NET, state management refers to the process of preserving data across different requests for the same user. ASP.NET provides various mechanisms to manage state:

View State: View State is used to preserve page and control values between round trips. It stores the state of the page and its controls in a hidden field on the page, which is sent to the client and back to the server with each request/response. It is suitable for retaining small amounts of data specific to a single page.
Session State: Session State allows you to store and retrieve values for a user as they navigate an ASP.NET application. Session State is stored on the server and is unique to each user session. It’s commonly used for storing user-specific information such as user preferences, shopping cart contents, etc.
Application State: Application State allows you to store global objects that can be accessed by all users of the application. It’s stored on the server and is common across all users. Application State is useful for storing data that is shared among all users, such as application-wide configuration settings or global variables.
Cookies: Cookies are small pieces of data stored on the client’s machine. They can be used to store user-specific information, such as user preferences or authentication tokens. Cookies are sent back and forth between the client and server with each request/response.
Query Strings: Query Strings are a way to pass information from one page to another via the URL. They are appended to the URL as key-value pairs and can be accessed on the destination page using server-side code.
Control State: Control State is similar to View State but is specifically designed for storing the state of custom server controls, ensuring that it’s not disabled by the page’s view state.
Session-less State: ASP.NET also provides options for session-less state management where you can avoid using Session State if your application doesn’t require maintaining user-specific data across multiple requests.

When answering this question in an interview, you can provide a brief overview of each state management technique, highlighting their use cases, advantages, and any relevant considerations. It’s also a good idea to mention which scenarios are suitable for each technique and how to choose the appropriate one based on the requirements of the application.