San-Serif fonts have clean, curved and linear lines...no embellishments as in Serif fonts like Times New Roman. This font style has a very nice classic, even art deco look to it. This makes Sans-Serif fonts perfect for logos. The above graphic has three representative fonts: Arial, Impact and Opal. Notice the boldness of the Impact font style.
The Arial and Opal font styles are thinner, yet still have a good visual impact to the viewer.