FTP uses TCP because the file transfer has to be correct.
TFTP uses UDP for speed, but not everything will get there.
FTP uses TCP.Usage of Transport Layer protocol (tcp or udp) depends upon various applications.Such as FTP uses TCP, TFTP uses UDP.
UDP: DNS, TFTP, DHCP... TCP: SMTP, HTTP, HTTPS, DNS, FTP, SHH, Telnet...
TCP
If FTP did not have TCP working with it, it could be considered connectionless. TCP is connection oriented and it verifies the FTP transfers have been received. Therefore it is considered Connection Oriented. If FTP used UDP it would be considered connectionless as UDP just sends the data and never checks to see if it all made it to the recipient -
Aknowlagement
Yes, it does.
UDP is alot faster than TCP. So if its realtime obviously it has to be fast, thus UDP. The only problem is UDP isn't as reliable or as secure as TCP. But it does have the speed advantage.
UDP
UDP does not require as much resources as TCP but in the same time, it does not insure delivery of packets.
No it uses UDP packets.
FTP; HTTP; DNS (uses both TCP and UDP); several e-mail protocols including POP3, SMTP, IMAP4.
UDP and TCP both are transport layer protocols. UDP is connection less and TCP is connection oriented. UDP is preferred over TCP when large amount data is to be sent like on skype or video conferencing .