The word plaque can have different connotations:

• Dental plaque is a yellowish biofilm that build up on the teeth. If not removed regularly, it can lead to dental cavities (caries).
• In atherosclerosis, atheromatous plaque is a buildup of fatty deposits within the wall of an artery that narrows the artery, reducing blood flow and inducing turbulence in the blood blow. Atheromatous plaque contributes to stroke and myocardial infarction.
• A commemorative plaque can be a flat ornamental plate or tablet fixed to a wall, often used to mark a significant event, person, etc.
• A viral plaque is a visible structure formed by virus propagation within a cell culture.
• Plaque can additionally be used to refer to a (usually) small, disk-shaped growth on the human body, common in some forms of skin cancer.