These functions are used to work with TCP Sockets. TCP is used with a full connection, whereas UDP is connectionless. TCP also ensures that all packets reach the destination (when possible). TCP also ensures that packets are received in the same order as sent.
SDLNet_TCP_Accept - Accept a connection on a server socket
SDLNet_TCP_GetPeerAddress - Get the remote host address and port number
Based on jcatki's excellent SDL_Net documentation. See SDL_Net lib page for original.