Mobile devices such as smart phones, tablet computers, laptop computers, automobile computers, and smart cameras all provide additional functionality when connected to the Internet.  For example, a mobile device that is presently connected to the Internet can receive and send email messages; interact with websites; obtain the full benefit of executing applications that have a backend component; download new programs, program updates, and media artifacts; access remote files; etc. 
Typically, mobile devices connect to the Internet via wireless communications channels.  Many mobile devices are equipped to connect to the Internet via cellular data networks operated by wireless telephony carriers.  Some mobile devices are not so equipped, however, and those that are may incur significant marginal charges for sending or receiving significant volumes of data via cellular data networks. 
Virtually all mobile devices are equipped to connect to the Internet via Wi-Fi networks using networking protocols specified by variants of the IEEE 802.11 standard.  Because Wi-Fi networks are often free or inexpensive to use, and can in some places provide Internet connectivity where cellular data networks cannot, many mobile devices are configured to frequently scan for available Wi-Fi networks, such as at any time when the mobile device is not already actively connected to a Wi-Fi network.  Performing such scanning enables the mobile device to automatically connect to already-known Wi-Fi networks, and notify its user of new Wi-Fi networks within connection range that the user can choose to connect to.