Ideally, a CPUStands for "central processing unit." Basically, it's a microprocessor - the main one in the computer. Things get a bit more complicated because, these days, there may be more than one microprocessor. But you can safely think of all of them together as the CPU. executes instruction after instruction, with no breaks. But there are times when there may be a delay – getting new data from DRAMStands for "dynamic random access memory." This is temporary working memory in a computer. When the goes off, the memory contents are lost. It's not super fast, but it's very cheap, so there's lots of it. or having to reload the pipelineA way of speeding up a repeated task by breaking it up into stages and having different resources do each stage. It takes longer for the first task to be completed (that’s the latency); the others come out in quick succession after the first one. due to a branch, for example. When this happens, we say that the systemThis is a very generic term for any collection of components that, all together, can do something. Systems can be built from subsystems. Examples are your cell phone; your computer; the radio in your car; anything that seems like a "whole." briefly “stalled.”