I got to the section of our class text that discusses Recursion, and it makes no sense to me, maybe you guys can help?

Recursive Processes

Many problems can be solved by having a subprogram call itsself recursively as a part of the solution. Recursion is frequently used in math. Consider for example the definition of n! (n factorial) for a nonnegative integer n. This is defined by

0! =1
1! =1

for n >1,n!=n * (n-1)!

thus, 6!=6*5!=6*5*4!=6*5*4*3!=6*5*4*3*2!=6*5*4*3*2*1

huh??!!