How do garage door opener codes work?

The internal settings on garage door openers are connected to the garage door receiver, and once they are connected to one another, the remote uses a rolling code to connect to the receiver. The remote changes the connection code after each use so that the code cannot be stolen and replicated.

After the remote is connected to the receiver through radio frequencies, the rolling code system creates a new access code after every use of the remote to operate the garage door. The remote frequencies, which are measured in MHz, vary depending on the manufacturer, and users must use a remote with a matching frequency to the receiver for it to operate.