Final answer:
The connect() function is used by a TCP client to establish a connection to a server, after creating a socket, by specifying the server's address and port number. It sets up a reliable two-way communication channel upon success, and proper error handling is required if the connection fails.
Step-by-step explanation:
The connect() function in the context of TCP sockets is used by a client to establish a connection with a server. When programming a client in a socket-based network application, after the socket is created using socket(), the connect() function is used to initiate a connection to a specified server defined by an address and a port number.
In practical use, a TCP socket must be associated with a remote server's address and port to facilitate two-way communication, which is done through a network protocol such as the Internet Protocol (IP). The connect() function requires the address structure, usually in the form of sockaddr, that includes the IP address and port number of the server to which you're attempting to connect.
Upon successful execution, the client's socket is ready to use, enabling the client to send and receive data from the server over a reliable, ordered, and error-checked channel known as the TCP connection. If the call to connect() fails, the client program will typically detect an error allowing for proper error handling or a retry mechanism.