How UDP sockets differ #

• It uses the SOCK_DGRAM socket type.
• Using connect() can be optional with the use of sendto() and recvfrom().
• Sockets in TCP requires managing a socket for each peer connection while UDP needs only $1$ socket to communicate with any number of peers.
• listen() and accept() are not required in UDP since it only needs to bind to a local address which can then immediately send and receive data.

UDP Client Flow #

With connect() #

1. getaddrinfo()
2. socket()
3. connect()
4. send()
5. recv()
6. close()

Without connect() #

1. getaddrinfo()
2. socket()
3. sendto()
4. recvfrom()
5. close()

UDP Server Flow #

1. getaddrinfo()
2. socket()
3. bind()
4. sendto()
5. recvfrom()
6. close()