Wikipedia is a great encyclopedia, a project in which work and peer collaboration, play an essential role. That’s why it’s free and maybe an unlimited resource.
The difference is that google is not free, you will say that you do not have to pay to use their applications and that is true, but Google, as any company (for profit), earn money and much with our data and more.
Yes, apps are fantastic and what we can do with them too.
Although both initiatives among large differences, I must say that collaborative work is the most rewarding in my point of view.
Here is a video that show us the in a nice way how Google make money.