Bulletin board stickers are a type of adhesive sticker that can be used to post notices, reminders, and other information on bulletin boards. They are usually made of paper or plastic and come in a variety of shapes and sizes. Tacks are a type of fastener used to attach items to a surface, such as bulletin boards. They are typically made of metal and have a sharp point at one end for piercing the material being attached. Tacks are often used in conjunction with bulletin board stickers to ensure that the stickers stay in place.