This is a simple SPDT slide switch - great for use as an ON/OFF button, or just as a general control switch. The pins are spaced by 0.1", so it's breadboard friendly. The package contains 10 switches.
A simple tact button, also known as a 'push button', commonly used on Arduino boards as user/boot/reset button, 6x6 mm, breadboard friendly, pack of 10.