FOIL= first, outside, inside, last
These refer to the position of terms in the parentheses and the order they are multiplied.
Example:
(x+1)(x+2)
multiply first positions (far left)
(x*x)
then multiply the two outside
(x*2)
multiply inside terms
(1*x)
multiply last terms (far right)
(1*2)
Solution to example:
(x+1)(x+2)
(x*x)+(2*x)+(1*x)+(1*2)
combine terms
x^2+3x+2
Hope this helps! :)