FTP; HTTP; DNS (uses both TCP and UDP); several e-mail protocols including POP3, SMTP, IMAP4.
TCP
TCP
That would render most protocols useless. TCP provides the reliability that is required for many applications.
It does. see the tcp video tutorials
list 2 major types of internet application and their use
UDP
HTTP works over a TCP connection.HTTP works over a TCP connection.HTTP works over a TCP connection.HTTP works over a TCP connection.
A Local Area Network (LAN) is not directly connected to TCP (Transmission Control Protocol); rather, TCP is a protocol that operates at a higher layer in the networking stack. A LAN provides the physical and data link layers for connecting devices, while TCP functions at the transport layer to facilitate reliable communication between applications over a network. In a typical setup, devices on a LAN can use TCP to transmit data packets over the network, often in combination with IP (Internet Protocol).
UDP
You should use "netstat":netstat -p TCP
No, TCP/IP is the not the only protocol used in the world, but it is certainly one of the most popular. Older networks may still use IPX/SPX (Novell) which is a competitor to TCP/IP. Mainframes use SNA or LU6.2 protocols which are very different from TCP/IP. Appletalk is also a competitor to TCP/IP.
Aknowlagement