What is meant by the matrix of a relation?

The matrix of a relation is a binary representation of the relation defined on a set. If we have a set with ( n ) elements, the matrix is an ( n \times n ) grid where each cell indicates the presence (1) or absence (0) of a relation between the corresponding elements. For example, if an element ( a_i ) is related to element ( a_j ), the cell at row ( i ) and column ( j ) in the matrix will contain a 1; otherwise, it will contain a 0. This matrix provides a convenient way to visualize and analyze the properties of the relation.