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<img src="https://cdn.kahimyang.com/resources-24/client-server.avif" loading="lazy" alt="TCP/IP in C++" />
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<h4>
Understanding TCP/IP
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<p>
The TCP/IP model consists of four layers:
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<b>Network Access (or Link) Layer</b>: This layer handles the physical connection between devices and the network.
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<b>Internet Layer</b>: This layer is responsible for routing data packets across the network.
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<b>Transport Layer</b>: This layer ensures reliable data transfer between hosts using protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
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<b>Application Layer</b>: This layer provides network services to applications, such as HTTP for web browsing and SMTP for email.
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<h4>
Steps to Perform Network I/O in TCP/IP
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<b>Establishing a Connection</b>.  To perform network I/O, the first step is to establish a connection between the client and server. This involves: 
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<i>Creating a Socket</i>: A socket is an endpoint for sending or receiving data. In TCP, a connection-oriented protocol, a socket is created using the socket() function. 
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<i>Connecting to the Server</i>: The client uses the connect() function to establish a connection to the server's IP address and port number.
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<b>Sending Data</b>.  Once the connection is established, data can be sent from the client to the server using the send() function. This function sends data to the connected socket.
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<b>Receiving Data</b>.  The server can receive data sent by the client using the recv() function. This function reads data from the socket.
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<b>Closing the Connection</b>.  After the data exchange is complete, the connection should be properly closed using the close() function to free up resources.
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Basic C++ Client-Server Setup for TCP/IP Communication