Do you know what a digital certificate is and what it's for? A digital certificate is the electronic identity of a person or company. It works as a virtual ID card and allows you to sign documents remotely with the same legal value as the signature made in your own hand on paper, but without having to recognize the notarized signature.
A1 Certificate
It is issued and stored directly on a computer and is valid for one year.
A3 Certificate
It is stored in a token (which is similar to a pendrive) or in a smartcard that needs a specific reader. both of which can be valid for one, two or three years.
BirdID Certificate
Stored in the Cloud