What is the difference between "tcp" and udp"?

الاجابات كلها قريبه وصحيحه اضيف ان tcp بطيئ بالمقارنه ب udb 

the data transmission is reliable in TCP. not reliable in UDP

all above right

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol)

TCP - Connection Oriented Protocol, Performs Sequencing of packets along with error checks and send acknowldgements back to the sender, if no acks are recieved by the sender then the packet is sent once again

Mapped to Transport Layer

Very Reliable.

UDP Connectionless, unreliable

Does not send or recieves Acks 

Hence is considered faster (Ofcourse at the cost of reliablity)

Example: Youtube Video Stream , Voice over ip

• TCP is a connection oriented stream over an IP network. It guarantees that all sent packets will reach the destination in the correct order. This imply the use of acknowledgement packets sent back to the sender, and automatic retransmission, causing additional delays and a general less efficient transmission then UDP.

• UDP a is connection less protocol. Communication is datagram oriented. The integrity is guaranteed only on the single datagram. Datagrams reach destination and can arrive out of order or don't arrive at all. Is more efficient than TCP because it uses non ack. It's generally used for real time communication, where a little percentage of packet loss rate is preferable to the overhead of a TCP connection.

• In certain situations UDP is used because it allows broadcast packet trasmission. This is sometimes fundamental in cases like DHCP protocol, because the client machine hasn't still received an IP address (this is the DHCP negotiaton protocol purpose) and there will be any way to establish a TCP stream without the IP addreess itself.
• UDP is used in DNS and DHCP

• TCP is connection oriented and reliable where as UDP is connection less and unreliable.

  TCP needs more processing at network interface level where as in UDP it’s not.

  TCP uses,3 way handshake, congestion control, flow control and other mechanism to make sure the reliable transmission.

  UDP is mostly used in cases where the packet delay is more serious than packet loss.

  ADVANTAGES OF TCP (1) TCP always guarantees three things - your data reaches its destination,it reaches there in time and it reaches    there without duplication. (2) in TCP, since all the work is done by the operating system, so you just need to sit back and watch the show. Even the debugging is taken care of by your OS. (3) It automatically breaks up data into packets for you. (4) It is slower in functioning than UDP DISADVANTAGES OF TCP (1) since, all the work is being done by your OS, so if there are bugs in your OS, then you will face many problems like problems in surfing and downloading contents from the net. (2) TCP cannot be used for broadcast and multicast connectionsADVANTAGES OF UDP (1) Broadcast and multicast connections are available with UDP which is not the case with TCP. (2) It does not restrict you to connection based communication model (3) Much faster than TCP DISADVANTAGES OF UDP (1) There are no guarantees with UDP. It is possible that a packet may not be delivered, or delivered twice, or delivered not in time.   (2) you have to manually break the data into packets

TCP: Reliable connection oriented ,Heavyweight

UDP:UnReliable connectionless,lightweight

Summary:

(1) TCP is connection oriented and reliable where as UDP is connection less and unreliable.

(2) TCP needs more processing at network interface level where as in UDP it’s not.

(3) TCP uses,3 way handshake, congestion control, flow control and other mechanism to make sure the reliable transmission.

(4) UDP is mostly used in cases where the packet delay is more serious than packet loss. (Real time applications)

TCP

Connection Oreinted , Slow , Use Acknolegment , Use sequence number , Flow Control

UDP

Connectionless , Fast , No Acknolegment are used , No Sequance number are used , No Flow control just send don't stop " overhead "

TCP: (HTTP,HTTPS,FTP etc can use the TCP service)

1. Connection Oriented

2 .Error Connection

3. Acknowledgement

UDP: (DHCP and TFTP can use the UDP services) 

1. Connection less

2. Acknowledge less

Note: DNS can use the both services