Magic square is a square of an array of positive integers, arranged in such a manner that the sum of the numbers in any row, any column and any main diagonal remains the same.
If the numbers start from 1 onwards, the squares are called a normal magic squares.
An example for a three row and three column magic square is
Magic squares formed with alphabets are called Templar magic squares. The letters in the first row and first column are the same. So also the letters in the second row and second column and so on. The words will make a meaningful sentence.
Ancient Romans knew about the Templar magic squares. A Templar magic square found in the ruins of Pompeii has this Latin sentence arranged in the square.