Casting on basically means creating your stitches so that you can start knitting them – kind of like the foundation of knitting.
There are a few different ways to cast on but I’m only going to show you one to keep it simple. This way is my favourite because it’s really similar to knitting so once you know how to cast on, you can basically knit already (genius!)
Your knitting pattern will tell you how many stitches to cast on
Below is a printable of casting on step-by-step.