I'm having difficulty understanding this concept and would appreciate help
Factoring by grouping is convenient when there is no common factor among all your terms.
Take for example:
xy + 2y + 3x + 6
There is nothing common to all 4 of these terms, so we can try to factor by grouping instead.
Split the quadratic into 2 groups:
Now factor each of these 2 groups:
Since the (x+2) is common to both this can be factored out: