A robot is a machine that is capable of autonomously completing tasks. Depending upon the robot, these tasks may be simple or complex and may require little human intervention or complete oversight.
In the Fallout universe, robots had been constructed for many purposes, and many examples survived long enough to be a factor post-War.
Robots had been constructed by pre-War society to fill all niches and occupations. From general-purpose utility droids to full-fledged military battle machines, robots could be found in almost any environment and function. Some of the robots in the Fallout universe will attack immediately but some will aid in battle or remain ambivalent.