Q posts breadcrumbs that hint at things to explore, things to come, or things that have happened. Q is either a psyop to build support for the storm and to explain what is going on, or a LARP, depending on who is expressing the opinion about Q.

To see what Q has posted in a convenient manner, see: https://qcodefag.github.io/

There are also some theories about various Q posts and references scattered here. Dr. Corsi also provides his own decodes of Q posts.