Robot

A robot is a machine, especially one programmable by a computer, capable of carrying out a complex series of actions automatically.

They are different than an android, which is a synthetic organism designed to mimic living creatures.

Known Robots

 * Hulk (Robot)
 * Iron Man (Robot)
 * Machine Men
 * Master Mold
 * Sentinels
 * Spider Seeker
 * Spider-Slayers
 * Black Widow
 * Black Widow II
 * Tarantula
 * Scorpion (Robot)
 * Mega Slayer
 * Sleepers
 * Ultron

History
Human Torch was an android.

Red Skull had Andre Cocteau build him the Sleeper robots during World War II.

Henry Peter Gyrich and Bolivar Trask built the Sentinels and Master Mold to hunt down mutants.

Kingpin and Norman Osborn had the Spider-Slayers built to defeat Spider-Man.

Mandarin built a robotic copy of Iron Man.

Thaddeus Ross built a robotic copy of Hulk.

Ant-Man built Ultron, who then built the android Vision.

Background
Robots were popular for Saturday morning cartoon shows at the time because censors were more lenient about violence against them than against living creatures.