TLS (Transport Layer Security) and SSL (Secure Sockets Layer) are protocols that provide data encryption and authentication between applications and servers in scenarios where that data is being sent across an insecure network, such as checking your email. - SSL versus TLS – What’s the difference?
- A program can initiate a secure connection with a server by Port ('explicit' - SSL), or by Protocol ('implicit' - TLS)
- A negotiation between the client and the server determines which protocol is used. This is based on which software is installed on each and how each is configured.