Singular matrix : A square matrix that doesn't have an inverse is called singular matrix.
A square matrix is said to be singular If and only if it's determinant | A | = 0
Ex: ⌈ 1 4 ⌉ ⌊ 2 8 ⌋
| A |= ( 1 x 8 ) - ( 4 x 2 ) = ( 8 - 8 ) = 0 as it's determinant | A | = 0 this square matrix has no inverse so it is a singular matrix.
Non-Singular matrix: A square matrix that has an inverse is called non-singular matrix.
A square matrix is said to be non-singular if and only if it's determinant | A |≠ 0
Ex: ⌈ 2 -4 ⌉ ⌊ 1 6 ⌋
| A | = ( 6 x 2 ) - ( 1x -4 )= ( 12 ) - ( -4 ) = 16, as | A | ≠0 this square matrix has inverse so it is non-singular matrix.