Why TCP is reliable protocol?

Related questions

1. When would you use UDP?
2. Why is UDP connection less?
3. Is UDP used?
4. How reliable is TCP?
5. Is multicast TCP or UDP?
6. Why checksum is used in UDP?
7. Why UDP is not reliable?
8. Why is TCP Reliable and UDP unreliable protocol?
9. What is the function of UDP?
10. Why is UDP connectionless?

Tags

1. #reliable
2. #everything
3. #packet
4. #protocol
5. #receiving
6. #delivered
7. #transmitted
8. #considered
9. #control
10. #reason
11. #itself
12. #transmission
13. #checks