What Am I Riddles

Question: Wind and cord combine, buzzing in the box. In all this we find, though to some the use is lost. What am I?

Question: What can you serve but never eat?

Question: What belongs to you but others use it more than you do?

Question: What has a foot but no leg?

Question: Crawls over pages and fells wild beasts.
Helps guide you along in your home and on streets.

What is it?