Knitting in the round/ on circular needles means that you can create your knitting in a loop so there’s no seams, you just keep knitting round and round, one of the advantages of this is that you don’t need to do any sewing up! Like many knitting techniques, circular needles can seem a bit daunting if you’ve never used them before, but they really are easy to get used to & great fun to knit with!
When casting on with circular needles, create all your stitches and then instead of turning for row 1, you keep your yarn taught and knit into the first stitch you created, making a ‘circle’ of stitches. just make sure your stitches aren’t twisted when you start to knit in the round.
I also advice use a stitch marker when knitting in the round to mark the beginning/end of each row. You can easily make a marker by loosely tying a piece of yarn around your needle. It helps you to easily keep track of where you are in your round. Simply slide it, without knitting it, each time you reach it.