Answer
The greatest common divisor of two or more natural numbers can be obtained by finding out the largest number that divides both the natural numbers.
For example, greatest common divisor of 8 and 12 is 4 as 4 completely divides both 8 and 12 as:
\[\begin{align}
& 8\div 4=2 \\
& 12\div 4=3 \\
\end{align}\]