In mathematics, a tuple is a finite sequence of objects. Sometimes the finite sequence is also called an ordered list. Each of the objects in the list has a certain type. A tuple consisting of n entries is called an n-tuple. Tuples are used to describe mathematical objects that are made of certain, well-defined components. They are also used very frequently with databases. Tuples are different from sets:
- A certain element can be in a tuple more than once.
- The order in which the elements appear is important.
In other words, tuples are like ordered multisets.