Web, domains and email
double opt-in
In short and in plain language
Double opt-in is a way to sign up where you confirm a second time.
After you sign up, you get an email with a link. You click on it and so confirm your sign-up.
This shows that the sign-up really came from the owner of the address. It is common in email marketing. It can help to prove consent.
Definition
Double opt-in is a sign-up procedure in which a person additionally confirms a registration via a link in an email. This makes it traceable that the sign-up really came from the owner of the address. The procedure is common in email marketing because it can help to document consent.