Simple definition
A TLS handshake negotiates cryptographic parameters, authenticates server identity, and establishes encrypted session keys.
Purpose and use
A TLS, Transport Layer Security, handshake establishes parameters and secrets needed for a protected client-server channel.
How does it work?
In TLS 1.3, Hello exchanges negotiate algorithms and contribute to key derivation; authentication messages allow peer verification according to the selected mode.
Example and verification
For HTTPS failures, distinguish protocol incompatibility, certificate error, requested hostname, trust chain and server settings.
Points to watch
A presented certificate is insufficient unless the client performs its checks. A successful handshake does not prove that the application authorizes or handles the next request correctly.
In short
TLS protects the channel according to negotiated parameters and validation; business authentication and access control remain application responsibilities.