Serif and San Serif

What is Serif and San Serif ?

• Serif is a small line, structural detail or flourish at the extremities of a type character.
• Sans-Serif is a type character without any of the above design.

What is the difference between Serif and Sans Serif ?

There are many categories of typefaces but we encounter these most. Identifying the difference between them is very simple.
See the below logo :

If you keenly observe 

Serif fonts have that extra stroke or decorative design on the end of letters. Where as sans-serif doesn't have any such design or stroke.

Example :

In quora, answers are serif other then that every thing is in san-serif.

Conclusion :

If you are designing logos or creating banners use serif. For designing magazines, newspapers and annual reports it's better to use san-serif.