GCF is the greatest common factor
Example:
6:1,2,3,6
12:1,2,3,4,6,12
Now their GCF is 36 because the common factors they have are multiplied:
1,2,3,6
Now LCM is the Least common factor:
Example:
6:1,2,3,6
12:1,2,3,4,6,12
Their highest common factor is 6 so the LCM is 6
