Security
Certificate
In short and in plain language
A certificate is a digital proof for a website.
It confirms who the website belongs to. It also makes the encrypted connection possible.
It is issued by a body that handles this.
When it runs out, browsers show warnings. Visitors may then no longer be able to open the shop normally.
Definition
A certificate is a digital attestation that confirms the identity of a website and enables the encrypted connection via HTTPS. It is issued by a certificate authority. Once it expires, browsers show warnings, and visitors may no longer be able to open the shop normally.