(1) A vertical computer cabinet. Large towers typically stand on the floor, but smaller units often reside on the desktop. In the past, numerous personal computers came in cases that were horizontal and designed only for the top of the desk. Today, most computers come in tower cases or are all-in-ones or portables (see all-in-one and laptop).

(2) A self-standing, vertical post that is designed to hold one or more antennas. Very often, the term refers to both the tower and antennas; for example, a cellular tower.