The name has for origin a very very big number: the googol in English, is 10 power 100, that is 1 follow-up of 100 zéros.
In 1997, when the creators of Google looked for a name, they asked studying in computing. One of them, Sean Anderson, finds
"googolplex". In English, the googolplex is a number even bigger than a googol, because it is 10 power googol, that is 10 power
10 power 100, that is 1 follow-up of a great deal of zéros, more of zéros than of atoms in the universe!
Larry Page, one of the 2 créateusr of Google, is seduced by a version shorter one, googol. He asks then to Sean Anderson to record the name.
There are then 2 versions of the history to explain how googol was transformed into Google:
In the first version, it would be quite simple an error of strike. Googol is accidentally transformed into Google.
In the second, the domain name googol.com was already taken, and it would have been decided to take something similar, google.com. Maybe 2 versions are true?
We can also note that Google chose Googleplex as name of its headquarters in California, very probably in wink to the "googolplex"