SSL/TLS
Also written as HTTPS, TLS Certificate
The protocol (TLS is the modern version of SSL) that encrypts data traveling between a client and server, and verifies the server is who it claims to be — the technology behind HTTPS.
Think of it like
Like sending a letter in a sealed, tamper-evident envelope with a wax seal proving who it's really from, instead of a postcard anyone along the way could read or fake.
Junior or senior?
Junior sounds like
Knows HTTPS is 'more secure' with no further detail.
Senior sounds like
Has handled an outage caused by an expired TLS certificate and can describe how they prevented it from recurring.
Ask them
“Have you ever dealt with an outage caused by an expired TLS certificate? What happened, and how did you prevent it from recurring?”