If you’re not aware, designers of all kinds argue about whether serif or sans serif fonts look and function better. This pertains to websites as well as products outside of the digital world. Don’t be embarrassed if you don’t know the difference between the two, because most people don’t.
Most people associated serif fonts with established design, classical composure, and formal presentation. Popular serifs include Times New Roman, Baskerville and Rockwell, to name a few.
With sans serif, you get a more modern feel to the font. While the different options can have a variety of widths and shapes, there are no extra flourishes that extend beyond the basic shape of the letters, numbers, etc.
The feelings communicated by sans serif fonts include minimalistic, clean, direct, and friendly. Among the sans serif fonts you might know is Arial, Helvetica and Futura.
It used to be that people thought there was a huge readability gap between sans serif and serif fonts. In reality, the readability depends on the exact font, the size you’re using, etc. and should be evaluated on a case-by-case basis.
Selecting a serif or sans serif font isn’t a straightforward process. Your font needs to go with the overall design of your page, including the feeling you’re trying to convey, colors, other shapes, images, etc. If you look at many great websites, they use a combination of serif and sans serif fonts. In other words, it’s a highly subjective question that really comes down to preference and messaging.