Initialism of Start-Stop Logic.
"The automotive engineer analyzed the SSL protocol to diagnose why the vehicle's engine stalled intermittently during startup."
In plain English: SSL is an old security system that made websites safe to use by encrypting data between your browser and the site's server before it was shut down for newer technology.
"The website uses an SSL certificate to keep your personal information secure while you shop online."
Initialism of Secure Sockets Layer (cryptographic protocols which provide secure communications on the Internet).
"The website uses SSL to encrypt data and ensure a secure connection between your browser and the server."