A mathematical relation is a way to describe a connection between two or more sets of values. It shows how elements from one set correspond to elements in another set. For example, in the relation between x and y, each value of x can be paired with a specific value of y, illustrating how they interact. Relations can be represented in various forms, such as tables, graphs, or equations. A common type of relation is a function, where each input from the first set has exactly one output in the second set. Understanding relations is essential in fields like mathematics, science, and engineering.