Can MySql handle Large data?

I want to quickly ask if MySql can handle large data like 10 – 20 million
rows in one database (e.g member table)

The question came to my mind is, How did large website like Yahoo handle
such data? Sure. Yahoo users may be more than 20 millions users or so.


Users will have -permission table
                      -profile table
                      -page table  and so on, so query will be perform on 2
or three tables same time, i`m trying to check the speed, performance and
risk .

I need your advice on how to handle such data and the best structure to use.