Everyone's heard "show, don't tell" at least once. It gets passed around in workshops, classes, and critique groups. It takes other forms, too. Sometimes it's labeled as "spoon-feeding" or "info-dumping," depending on the genre. It's probably the most common piece of writing advice ever given.
It's also the most meaningless.
"Show, don't tell" has a somewhat unfortunate history. It may be anti-communist propaganda, and it definitely has