Original: A matrix with one row (a 1 Ã - n matrix) is called a row vector, and a matrix with one column (an m Ã - 1 matrix) is called a column vector. Any row or column of a matrix determines a row or column vector, obtained by removing all other rows or columns respectively from the matrix.
Simplified: A matrix, that has many rows, but only one column, is called a column vector.