How do computers know what to do with binary 1’s and 0’s?

Question

I’m very interested in learning how computers work, but can’t seem to find the exact information I’m looking for. My understanding is, and **please** correct me if I’m wrong, is that if you press the letter “A” on a keyboard, a circuit underneath will close which sends electricity to wires, and based on the combination of voltages on the wires, the computer outputs an “A”. But how does the computer know what do to with voltages? What do the voltages represent? At what point does any of this information get converted into binary, and once it does, what happens?

I don’t expect someone to be able to explain this like I’m five. For me, it’s a difficult, but really interesting subject. Any clarification and dumbing down is appreciated! I’m really hoping to get a better grasp on my understanding of all this.

Edit: I should’ve made the title “How do computers work?” Still wondering how computers know what to do with 1’s and 0’s, though.

In: 0

Answer 1

The electronic components in a computer chip combine to form things called [logic gates](https://en.wikipedia.org/wiki/Logic_gate), which are devices that output a signal based on a combination of input signals. Each signal is either on (1) or off (0). You can think of them as little boxes that have some wires going in, and one wire coming out, and whether there’s electricity flowing on the wire coming out depends on the kind of box it is.

For example, an `AND` gate’s output signal will be on (1) if and only if both of its input signals are also on; otherwise, it’ll be off (0). An `OR` gate will be 1 if either or both of its input signals are 1; if both input signals are 0, the output will be 0. A `NOT` gate has only one input, and it inverts it — the output will be 0 if the input is 1, and vice versa.

These gates combine to make circuits that do specific things. One simple example is an [adder](https://en.wikipedia.org/wiki/Adder_(electronics)), which takes bits (0 or 1, represented by on or off signals) and combines them into multiple signals representing their sum.

Modern computers have hundreds of billions of transistors that probably form on the order of billions of logic gates, so you won’t be able to get a full picture of what’s happening by looking at simple circuits like this. But at the lowest level, this is how computers derive meaning from 1 and 0.