SSL: (Secure Sockets Layer) is a protocol layer between the network layer protocol and the application layer protocol for reliable connection. SSL realizes secure communication between client and server through mutual authentication, digital signature and encryption. The protocol consists of two layers: SSL recording protocol and SSL handshake protocol.

TLS: (Transport layer security) is used to provide confidentiality and data integrity between two applications. This protocol consists of two layers: TLS recording protocol and TLS handshake protocol.

SSL is specially developed by Netscape to protect Web communication, and the current version is 3.0. The latest version of TLS 1.0 is a new protocol formulated by IETF (Engineering Task Force), which is based on the SSL 3.0 protocol specification and is the subsequent version of SSL 3.0. There is little difference between the two, which can be understood as SSL3. 1, written in RFC.

SSL protocol is located between TCP/IP protocol and various application layer protocols, which provides security support for data communication. SSL protocol can be divided into two layers: SSL recording protocol, based on reliable transport protocols (such as TCP), provides support for high-level protocols such as data encapsulation, compression and encryption. SSL HandshakeProtocol: based on SSL recording protocol, it is used for identity authentication, encryption algorithm negotiation, encryption key exchange and so on. Before the actual data transmission.

SSL certificate is a kind of digital certificate (digital certificate includes SSL certificate, client certificate, code signing certificate, etc. ) because it is also called a server SSL certificate when configured on the server. SSL certificate is a digital certificate issued by a trusted digital certificate authority CA (such as Wotong CA) after verifying the identity of the server.