How it works
A push button is a simple mechanical switch that is momentary in action — it only closes the electrical circuit while it is being actively pressed down by a finger. As soon as the pressure is removed, a small internal spring pushes the contact back up, opening the circuit.
Push buttons (often called tactile switches) are widely used for user inputs on microcontrollers, reset buttons, and simple momentary triggers. Standard 4-pin tactile buttons actually consist of two pairs of internally connected pins, which can sometimes cause confusion during wiring.
Because they rely on metal contacts snapping together, they suffer from mechanical "bounce," just like any switch. A single press might register to a fast microcontroller as multiple rapid presses unless the signal is "debounced" using a small capacitor or software delays.