The term "Buff" has multiple meanings depending on its context.
1) In a general sense, it can refer to something that is worn or used to protect one's skin from injury while performing physical activities such as exercise or sports. This type of buff could be in the form of a cloth, leather, or other material that covers and cushions the body part being protected.
2) In computer science, "buff" can refer to an area of memory used for temporary storage of data before it is processed by a program. It stands for “Buffer”.
3) In slang terms, "Buff" could also mean something or someone that is physically attractive and well-built, often referring to muscular definition in the body. This usage is more commonly used when describing people rather than objects.