Access Control is the selective restriction of access to a place or other resource. The act of accessing may mean consuming, entering, or using. Permission to access a resource is called authorization.

Organizations of all sizes use time and attendance systems to record when employees start and stop work, and the department where the work is performed.

A proximity card or prox card is a "contactless" smart card which can be read without inserting it into a reader device, as required by earlier magnetic stripe cards such as credit cards and "contact" type smart cards. The proximity cards are part of the Contactless card technologies. Held near an electronic reader for a moment they enable the identification of an encoded number.