Found a lot similar font but does anyone know the exact font?

Arial  Suggested by marty666 

Sans Serif 14px

As Touficb said, the font design is a Sans Serif design.
But that's not the name of the font...

In their Cascading Style Sheet (CSS), Wikipedia don't specify which Sans Serif font the browser should use.
It depends on the user's computer. The only thing that the CSS asks is to use a Sans Serif font.

In the case of your screenshot, the font used is Arial and Arial Bold