What is the difference between HTTP and HTTPS?

HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) are two protocols used to transfer data between a client and a server. The main difference between them is security.

1. Security: HTTP is an insecure protocol, and all transmitted data is in plain text, which is easily intercepted and tampered by hackers. HTTPS, on the other hand, provides a higher level of security by encrypting and authenticating data using the SSL (Secure Sockets Layer) or TLS (Transport Layer Security) protocols.

2. Data transmission method: HTTP uses clear text transmission, and data is not encrypted during transmission. HTTPS uses the SSL/TLS protocol to encrypt data to ensure the security of data during transmission.

3. Port: HTTP uses the default port 80 for communication, while HTTPS uses the default port 443.

4. Certificate: When using HTTPS, the server needs to obtain an SSL certificate, which is issued by a trusted third-party organization to verify the identity of the server. In this way, the client can confirm its identity when establishing a connection with the server, and ensure that the data will not be tampered with by man-in-the-middle attacks.

To sum up, the difference between HTTP and HTTPS mainly lies in the security and encryption method of data transmission. HTTPS is more secure and reliable, and is suitable for websites and applications that need to protect sensitive information, such as banking and e-commerce. Since HTTP does not encrypt data, it is more suitable for general websites and applications that do not need to protect sensitive information.