A process loop describes the return to a previous activity or step in a process. This involves repeating the process path, to a certain extent. A loop often follows a decision, for example, it could be a result of controls. In the case of controls, loops mean that reworking is necessary. For example, when a password and username or email address are checked during a login process, if one of the two criteria is not correct, the check fails or must be corrected. In this example, the correction involves re-entering the login data.