Stack Overflow in Portuguese has certain questions related to development, but that are not about programming itself, due to the fact that Stacks in Portuguese are still very recent in relation to Stacks in general. In English, you can ask Graphic Design. In it there is even a question similar to yours:
How do I know if my downloaded font is legal ("How do I know I can legally use the source I downloaded")
And the answer is that each case is a case. You must search the individual license of each source. Unfortunately this is a job you should do for each different source you use. But maybe you can find some healed list for the most commonly used sources.
Each author publishes their sources under a different license. In general, anyone using Creative Commons releases them for non-commercial use without payment, but for commercial use you may have to pay for a license.
Now... Sans-Rif is not a source, it is a feature that several sources have in common. Sans-Rif means "without serif", which are a visual marking that facilitates reading for some people.
Several sources have Sans-Rif in the name, to make it clear that they do not have serifs, but only this does not define the name. Find your source name and check how your authors make it available for free or commercial use.
I even knew that sans-Serif is a feature, I must be confused. http://imgur.com/n8fSmKh
– Alex
I got that question again, and look here what I was talking about, about
sans-serif
https://www.myfonts.com/fonts/ascender/microsoft-sans-serif/licensing.html– Alex
@Marcelorafael
Microsoft Sans Serif
is the full name of the font. There are other fonts you also haveSans Serif
in the name.– Oralista de Sistemas