What is the difference between UDP and TCP?

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two protocols that operate at the transport layer of the Internet Protocol (IP) suite. They both provide a way for devices to communicate over a network. Still, they have some essential differences that make them better suited for different tasks.

Key Points

TCP and UDP protocols serve different functions in your daily internet activity.
Each protocol has its benefits and detriments.
TCP and UDP protocols have distinct speeds, which can help VPN users choose which one they want to use.

One of the main differences between TCP and UDP is their error-handling capabilities. TCP is a reliable protocol, ensuring that all data packets sent from one device to another are delivered successfully. It does this using a system of acknowledgments, retransmissions, and timeouts. If a packet is not acknowledged, the sender will retransmit it until it is received by the recipient. This ensures that all packets are delivered in the correct order. Still, TCP is slower than UDP because of the additional overhead involved in checking for errors and retransmitting packets.

On the other hand, UDP is an unreliable protocol. It does not guarantee that packets will be delivered and does not have any mechanism for retransmitting lost packets. This makes it faster than TCP, but it also means that it is not suitable for applications that require reliable data transmission.

Another difference between the two protocols is their usage. TCP is typically used for high-reliability applications, such as web browsing, email, and file transfer. UDP is often used for real-time applications that require low latency, such as online gaming, voice-over IP (VoIP), and video streaming.


In summary, the main differences between TCP and UDP are their error-handling capabilities and their suitability for different applications. TCP is a reliable protocol that ensures all data packets are delivered successfully, but it is slower than UDP. UDP is an unreliable protocol that is faster than TCP. Still, it is not suitable for applications that require reliable data transmission.

Suppose you are looking for a VPN that offers both TCP and UDP traffic. In that case, AstroVPN does this job quite nicely, maintaining more than a dozen locations with profiles for both protocols!