A relation in a database management system is a table or a collection of tables. These tables are used to define the attributes of an entity or data item that satisfies the relation and also exists in the database.
A relation is defined by a table, which consists of rows and columns.
Rows may be one, two or multiple since a relation can be held by many entities. Rows can also be termed as tuple or record as they are sufficient enough.
Columns are the fields or attributes that are the properties of the data items or entities. Columns can be used to make queries to result particular records, that satisfy the query.