In linear algebra, a matrix is a 2-dimensional array of numbers, symbols, or expressions arranged in rows and Columns with the same length. A matrix could be reduced as a submatrix of a matrix by deleting any collection of rows and/or columns.
Vectors can be considered matrices with a single row.
Square Matrix: it is a matrix with the same number of rows and columns.
Diagonal Matrix: it has values on the diagonal entries, and zero on the rest of the matrix.
Scalar Matrices: has equal diagonal entries and zero on the rest of the matrix.
Identity Matrix: it has 1 on the diagonal and 0 on the rest.
Zero Matrix (Null Matrix): it has only zeros.
Tensor: A generalized matrix(N-dimensional matrix), a finite table of numerical values indexed along several discrete dimensions.