ELI5: Explain Like I'm 5

Instruction set architecture

Instruction set architecture (ISA) is like a language that your computer can understand. It is a set of commands your computer needs to know in order to do different tasks. For example, one instruction might say "add two numbers together". Another instruction might say "move a file from one place to another". The ISA tells the computer how to do the tasks, just like a language like English tells us how to communicate with each other.