Matrix

Matrix- is a rectangular array of numbers, symbols, or expressions, arranged in rows and columns.
A matrix with m rows and n columns is called an m × n matrix or m-by-n matrix, while m and n are called its dimensions.

Elements or Entries- individual items in a matrix 

 2 rows and 3 columns or 2 by 3



Matrix Multiplication-two matrices can be multiplied only when the number of columns in the first equals the number of rows in the second.

Row Vectors-Matrices which have a single row

Column Vectors-Matrices which have  a single column 

Square Matrix-matrix which has the same number of rows and columns 

Infinite Matrix-matrix with an infinite number of rows or columns (or both)