What is TLS? Definition and explanations
TLS (Transport Layer Security) is the protocol that encrypts exchanges between a client and a server over the network, the successor to SSL. It provides three things: confidentiality of the content, its integrity in transit, and authentication of the server through a certificate. It is the S in HTTPS. Version 1.3, published in 2018, simplifies negotiation and drops weakened algorithms.
In one sentence
TLS encrypts network exchanges, guarantees their integrity and authenticates the server; it is the S in HTTPS.