Recently I realized that I don’t know the difference between processes & threads, so I looked it up (Wikipedia): basically each “program” running is one process. Multiple instances of one program (e.g. multiple browser windows) require one process each. One process can have one (single-threaded) or multiple threads (multi-threaded), e.g. a word processor would have a different thread inside the same process for the check-spelling-as-I-type functionality…

The most useful paragraph is this…