TLSv1.3 is, as 2022, the latest and best revision so far of the TLS protocol (Transport Layer Seccurity). The TLS protocol is the one used when you access websites in encrypted manner with HTTPS, but it serves also for encryption of e-mail traffic among workstations and servers.
What about older TLS versions ?
TLSv1.3 is since 2018 when first published, the succesor of TLS versions 1, 1.1 and 1.2. And before TLS there was SSL (Secure Sockets Layer) with versions 2 and 3, that are as of 2022 no longer supported due to their vulnerabilities.
What makes TLS v1.3 faster ?
TLSv1.3 uses a simplified TLS Handshake with only one round trip. Previous TLS versions used to need two round trips for handshake. The additional advantage of v1.3 is that resuming a connection with a server involves a zero round trip also known as 0-RTT resumption.
What is a TLS handshake ?
TLS Handshake is the process by which a server and a client make use of the server's public key to agree on a secret for symmetric encryption, a cipher suite and a hash mechanism. This scheme is said to be hybrid as it uses both asymmetric cryptography through the server's Public Key, and symmetric for the data transfer once agreed upon the secret.