Cookies vs Sessions Explained: Key Differences
Cookie and Session are two commonly used mechanisms in web development for storing user state information.
A cookie is a small text file sent by a server to a browser and stored on a user’s computer. It can be used to store user identification information, personal preference settings, and more. When a user visits the same website, the browser sends the corresponding cookie back to the server to help identify the user and provide personalized services. Cookies are stored on the client side, are stateless for the server, have a small capacity (usually not exceeding 4KB), and are relatively low in security.
A Session is a mechanism for servers to store user state information. When a user first accesses a website, the server will create a unique Session ID for that user and store it on the server. The server will also send this ID to the browser, usually in the form of a Cookie. Each time the user sends a request, the browser will send the Session ID back to the server, allowing the server to identify the user and provide the appropriate services. Sessions are stored on the server, are stateless on the client side, can store more data than Cookies, and are more secure.
Difference:
- Storage location: Cookies are stored on the client side, while Sessions are stored on the server side.
- Storage content: Cookies store simple data such as user identifiers and personal preferences, while Sessions can store more complex data.
- Storage capacity: Cookies have a smaller capacity (usually not exceeding 4KB), whereas Sessions can hold more data.
- Security: Cookies stored on the client side are easy to steal and tamper with, while Sessions stored on the server side are relatively more secure.
- State Management: Cookies are stateless for servers, so servers need to manage user status through Sessions.
