Why is it called cover song?

Related questions

1. What is the most recorded song in music history?
2. Who first sang the song yesterday?
3. What was the original name of the song yesterday?
4. Who owns the rights to the song help?
5. Is Happy Birthday the most sung song in the world?

Tags

1. #described
2. #recently
3. #performer
4. #rival
5. #originally
6. #musicians
7. #interpretation
8. #recorded
9. #group
10. #version
11. #tribute
12. #compete
13. #reworking
14. #updating
15. #decades
16. #original
17. #versions
18. #songs
19. #released
20. #cover