The phrase "button configuration" refers to how the buttons on a device or controller are arranged and set up. It determines what each button does and how it functions. Full definition
There's also a custom button configuration for those of you who don't like the default controls. (mechadamashii.com)
All the time, we are stuck with the stock button configurations of an e-reader. (goodereader.com)
On the plus side, mapping the extra buttons is practically effortless, and players will be able to use the pad's profile switch button for up to two custom button configurations. (techtimes.com)