If you are cold, you can wear that on the top part of your body. It usually has a zipper or buttons. It's like a coat, but shorter.
Jacket
You wear those to sleep.
Pajamas
You wear them on your feet. You have to put them on before you put on your shoes.
Socks
You wear this around your neck when it's cold.
Scarf
You wear them when it's sunny. They protect your eyes.
Sunglasses