What are the main characteristics of a relation in DBMS?

In a Database Management System (DBMS), a relation is represented as a table consisting of rows and columns. Each row, or tuple, corresponds to a unique record, while each column, or attribute, represents a specific data field. Relations must adhere to the principles of atomicity, meaning each attribute should hold indivisible values, and they must maintain a unique identifier, usually a primary key, to distinguish each record. Additionally, all entries in a column should be of the same data type, ensuring consistency within the relation.