A curtain rod is a long stick-like thing that you put up above a window. It helps to hold up your curtains so they don't fall down. Think of it like a hanger for your clothes, but for your curtains instead.
There are usually two little things called brackets that hold the curtain rod up on the wall. These brackets come with screws so you can attach them to the wall. Make sure the brackets are sturdy and secure so your curtain rod doesn't fall down either.
Once the brackets are in place, you can put your curtain rod into them. The curtain rod usually has little hooks or rings where you can attach your curtains. This way, you can slide your curtains back and forth easily when you want to let in or block out sunlight.
So basically, a curtain rod is a tool you use to hang up curtains, and it helps to keep them in place so they don't fall down.