Buttons are a small rectangular block that when pressed, will release a temporary electrical current until the button resets (a second or so). Buttons can be made with either a (1) stone block to make a stone button or a (1) wooden plank to make a wooden button. (Unless things have changed, which for this, I doubt). So far, wooden buttons always match oak wood.
The button can be used for purposes that involve a temporary redstone current, like opening a door or powering a powered rail to start a minecart, but is not recommended for things that require a constant electrical current to function, which then requires a lever, if you want to turn it off, a redstone torch if you don't really want to turn it off, or (check validity) a block of redstone. It is also not recommended if you want a very short pulse, in which case if you want a single pulse you would use it but with a pulse-forming redstone circuit of some sort.
- When a button is placed on a side of a block with a redstone torch on top and is activated, the torch will turn off and the button will be stuck in pressed position until the torch is removed.
- Buttons are most common within strongholds (stone variety).