Absorbs energy thru hands
The Androids; 16, 17, 18, and 19 were created by the evil Dr. Gero who is also an Android: Number 20. When Trunks comes back in time, he warns the gang of the Androids, which will come, and with their enormous power, will terrorize the Earth. This is in three years time. Trunks says he will come back when the Androids arrive to help with the battle.
The gang trains hard for the coming threat. When the three years passes, as predicted, the Androids appear. Goku first fights them, and has the upper hand in the fight until a heart virus afflicts him, and he is unable to battle. Vegeta comes into the battle and kills off 19 easily. 20, who realizes he has no chance of winning, runs off to his lab and activates 16, 17, and 18. They turn around and kill Dr. Gero. They are much more powerful than 19 and 20.
The fight between the Z fighters and the Androids is pretty much even until Cell, Dr. Gero's secret creation, comes into the scene and absorbs 17 and 18. This transforms him into Perfect Cell.
16 is badly beaten up by Cell, but is then taken back to Bulma who re-assembles him and programs him to fight for the good side.
Cell regurgetates Android 18 in his fight with Gohan. She is taken in by Krillin who falls in love with her. She is wished into a human by the Dragon and Krillin and her end up marrying.
Android 18 participates in the World Fighting Tournament, and gets to the final bout, but then loses on purpose to Hercule, for 20 million dollars, which is twice the amount of the prize money.