Operator

Operator refers to the human component of a Tenno, the actual person who forms the Tenno's core identity, and whose powers are the source of a Warframe's abilities. A Warframe cannot be called a Tenno if there is no Operator from which said Warframe's powers and persona originate from.

As a game mechanic, a player acquires their Operator at the conclusion of the Second Dream quest, whose importance lies in improving their grasp of the Tenno's five great schools in the form of the Focus system.