Envelope

An envelope is like a little house for your letter or card. It's made of paper or plastic and folds up to keep your message safe and private. You put your letter inside the envelope and then lick the sticky part of the flap to seal it shut. The envelope has a place for the address and stamp so that it can be delivered to the person you're sending it to. It's like putting your message in a secret hiding place and then sending it off on an adventure to someone else's mailbox.