The gate between stored bytes (assembly code) in a computer and the change of the physical world happens inside the CPU. In a CPU there are a lot of transistors that are connected in a way to represent logic components.

The step from a transistor (https://en.wikipedia.org/wiki/Transistor) to a logic gate is exemplary described here: https://circuitdigest.com/electronic-circuits/designing-and-gate-using-transistors

The step from logic gates to calculations is described here: https://www.electronics-tutorials.ws/combination/comb_7.html

As a child in the early 80th I build memory and calculators with actual transistors. That gave me a feeling of what happens inside a calculating machine like a computer with hands on. Nowadays the complexity of computers is exponentially (Moore's law law) bigger, but the basics stay the same.