Most, if not all, developers make heavy use of a shell even if, like me, they run those shells from within Emacs or some other editor. There are lots of shells, of course, but the default these days is almost certainly bash. Ian Miell has two nice posts that explain some of the finer points of bash use.
Even as a long-term bash user, I learned a few things I didn’t know. For example, did you know that bash supports associative arrays? It does and Miell tells you how to use them. There’s lots more so be sure to give the two posts a read.