Although Dictionary.com makes no mention of it, for years and years I have heard that a google is the largest number that is classified. An example, 1000 is a one with three zeros after it; one million has six zeros and one 1,000,000,000 has 6 zeros. Of course, then there is a trillion, quadrillion and so on. A google is a number that is a "1" with 100 zeros after it. And there's really no need for it - or for any other number larger - except for maybe in some wild scientific computations - theoretical staff.

On the other hand, a "googolplex" (not googleplex) is the number 10 raised to the power googol, written out as the numeral 1 followed by (10 raised to the 100th power) zeros.