Why was the silicon chip so important in the computer industry?

The silicon chip is in many devices today....ex. mp3 players. It was a major breakthrough because it allowed more technology to be stored in portable or smaller devices. Almost everything has a silicon chip..even your cell phone. Particularly the computer industry it was important to forthe same reasons. The ipad is a computer, so is the iphone. But they wouldn't be possible without the silicon chip:)