A square matrix in which all the diagonal entries are 1 and the rest are all zero

A square matrix in which all the elements lies below the main diagonal are zero

A square matrix in which all the elements lies above the main diagonal are zero

A square matrix which is either upper triangular or lower triangular

A symmetric matrix with zeros in the off-diagonal elements

Unit matrix

Upper triangular matrix

Lower triangular matrix

Triangular matrix

Diagonal matrix