So i downloaded a font and there was a licence file and in it it writes that,,This Font Software is licensed under the SIL Open Font License, Version 1.1.'' Does it means that i can use the font commercialy ?

Please be more specific : which font did you download?

i downloaded this one http://www.dafont.com/lobster.font ?

Public domain / GPL / OFL....
http://creativecommons.org/tag/gpl

Could you just say can i use it for commercial use Yes or No ?

Just read. But be careful, you might learn something.

ThirdDimension, Lobster is a donationware font, meaning that you can use it commercially, without paying anything to the author, but you also can make a donation of any amount to the author or his chosen payee.

Why would someone pay for the font, if they don't have to? It depends on who wants to use it. If it's a regular Joe making a flyer, he may chose to pay nothing. If it's a magazine or a large corporation, they may make a sizable donation, if they would otherwise have had to purchase a license for an existing commercial font, or if they would have had to pay a graphic designer to create an equivalent custom text. The commercial model is based on the user's financial means, and the value they place on their use of the author's work.

This is all based on the assumption that the designer, Pablo Impallari, has not changed the licensing terms since the font was initially released.

The 'Apache' license he uses also allows users to modify glyphs, (but why would you want to?), so presumably, if you needed an accented character that is not already included in the font, you would be allowed to create one, based on a glyph already in the font.

So that means that i can use it commercially.Thank you metaphasebrothel helped me out a lot