Screen printing is the process of making images using a metal or wood screen supporting a fine mesh. To make the print, you use some kind of stencil to push ink through the screen and onto paper (or fabric) below. There are several ways you can make a stencil. You can cut one out of paper, and stick it to the screen. This is what I teach in the simplest of screen printing workshops.
To get more detail and a more consistent result, you can create a stencil within the mesh itself, using a photosensitive coating, and exposing that to UV light. This is what I teach in day long workshops at Arienas Collective. There are a couple of options, one for making multi-coloured prints with two or more layers of colour, and one where I share my techniques for applying imitation gold leaf to your prints too.
Check the Arienas Collective for Upcoming Dates