Https (Secure Hypertext Transfer Protocol) is a secure version of the http protocol, which protects data transmission through encryption and authentication. It uses SSL (Secure Sockets Layer) or TLS (Transport Layer Security) protocol to encrypt communication, thus ensuring the safe transmission of data between the client and the server.

The differences between https and https are as follows:

Data encryption: https uses SSL/TLS protocol to encrypt the transmitted data. This means that the data transmitted through https is encrypted during transmission, and the third party cannot easily eavesdrop or tamper with the data. In contrast, the data transmitted by http is plaintext, which is easy to be eavesdropped and tampered by attackers.

Authentication: https authenticates the server before data transmission. The server uses SSL certificate to prove the authenticity and credibility of its identity. In this way, the client can verify the identity of the server and ensure that a connection is established with a legitimate server. Http does not provide authentication mechanism, so it is impossible to verify the authenticity and credibility of the server.

Port number: http uses port 80 for communication by default, and https uses port 443 by default. This enables network devices and firewalls to distinguish and filter http and https traffic according to port numbers.

URL prefix: In the browser, the URL prefix of websites accessed through https is "https://", while the URL prefix of websites accessed through http is "http://". This is a way for the browser to identify the connection type and security.