Important points:

Server side

1. Load socket library;
2. Set up socket;
3. Server address filling;
4. Bind the socket and address of the server;
5. Enable monitoring;
6.accept waits for the connection to obtain the client socket;

Bottom line: bind server address to server socket, ready to accept client connection.

Client

1. Load socket library;
2. Establish client socket;
3. Fill in the sever address; / / note that there is no wrong writing here, or you need to know the server address
4. Actively connect to the server (client and server addresses are required);

Bottom line: client socket requests connection from server address.

Code

#include<WinSock2.h>
#include<stdio.h>
#pragma comment(lib, "ws2_32.lib")

int main(){
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2,2),&wsaData);
	if(LOBYTE(wsaData.wVersion)!=2 || HIBYTE(wsaData.wVersion)!=2)
	{
	  printf("Request version failed"); 
	  return -1;  
	}
	
	SOCKET serverSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	if(INVALID_SOCKET == serverSocket)
	{
		printf("Socket creation failed");
		return -1;    
	}
	
	SOCKADDR_IN serverAddr = {0}; //Initialization protocol address
	serverAddr.sin_family = AF_INET;//Must be consistent with the IP protocol for socket creation
	serverAddr.sin_port = htons(8080);    //Server port, through which clients connect
	 
	//ip address is a string in dotted format, which is used to convert integers with INET  addr
	serverAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	
	if(SOCKET_ERROR == bind(serverSocket , (SOCKADDR*)&serverAddr , sizeof(serverAddr)))
	{
	  printf("Binding failed");
	  closesocket(serverSocket);  //Release socket
	  WSACleanup();  //Close socket
	  return -1;  
	}
	printf("Binding success");
	
	if(SOCKET_ERROR == listen(serverSocket, 10))	//10 indicates the maximum listening queue size 
	{
	  printf("Monitoring failed");
	  closesocket(serverSocket);  //Release socket
	  WSACleanup();  //Close socket
	  return -1;  
	}
	printf("Monitoring success");
	
	SOCKADDR_IN clientAddr = {0};
	int len = sizeof(clientAddr);
	SOCKET clientSocket = accept(serverSocket,(SOCKADDR*)&clientAddr, &len);    //Blocking function. If the connection is successful, clientAddr will be filled by the client address, and a clientSocket will be returned for receiving and sending
	if(clientSocket == INVALID_SOCKET)
	{
	  printf("connection failed");
	 closesocket(serverSocket);    //Release socket
	 WSACleanup();   //Close socket
	  return -9;
	}
	printf("Successful connection");
	printf("Client(%s)\n" , inet_ntoa(clientAddr.sin_addr));
	
	char recvBuff[128] = {};
	while(1)
	{
	  memset(recvBuff, 0 , sizeof(recvBuff));
	  if(recv(clientSocket , recvBuff, sizeof(recvBuff)-1 , 0) >0)  //Blocking function
	  {
	       printf(">>%s\n" , recvBuff);
	  }
	    
	  char sendBuff[128] = {};
	  memset(sendBuff, 0 , sizeof(sendBuff));
	  printf("Please input:\n");
	  scanf("%s" , sendBuff, sizeof(sendBuff)-1);
	  //Primary transceiver  
	  send(clientSocket , sendBuff, strlen(sendBuff), 0);  
	}
	
	
	closesocket(clientSocket);
	closesocket(serverSocket);
	WSACleanup();
	return 0;
}

#include<WinSock2.h>	//The socket interface is stored here 
#include<stdio.h>
#pragma comment(lib, "ws2_32.lib")	//This is the socket implementation library, which means to connect to this library 

int main(){
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2,2),&wsaData);
	if(LOBYTE(wsaData.wVersion)!=2 || HIBYTE(wsaData.wVersion)!=2)
	{
	  printf("Request version failed"); 
	  return -1;  
	}
	
	
	SOCKET clientSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	if(INVALID_SOCKET == clientSocket)
	{
		printf("Socket creation failed");
		return -1;    
	}
	
	SOCKADDR_IN serverAddr = {0}; //Initialization protocol address
	serverAddr.sin_family = AF_INET;//Must be consistent with the IP protocol for socket creation
	serverAddr.sin_port = htons(8080);    //Server port, through which clients connect
	
	//ip address is a string in dotted format, which is used to convert integers with INET  addr
	serverAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	
	if(SOCKET_ERROR == connect(clientSocket , (sockaddr *)&serverAddr , sizeof(serverAddr)))
	{
	  printf("connection failed");
	 closesocket(clientSocket);    //Release socket
	 WSACleanup();   //Close socket
	  return -2;
	}
	printf("Successful connection");
	
	char sendBuff[128] = {};
	while(1)
	{
	  memset(sendBuff, 0 , sizeof(sendBuff));
	  printf("Please input:\n");
	  scanf("%s" , sendBuff, sizeof(sendBuff)-1);
	  //Primary transceiver  
	  send(clientSocket , sendBuff, strlen(sendBuff), 0);
	
	  char recvBuff[128] = {};
	  memset(recvBuff, 0 , sizeof(recvBuff));
	  if(recv(clientSocket , recvBuff, sizeof(recvBuff)-1 , 0) >0)  //Blocking function
	  {
	       printf(">>%s\n" , recvBuff);
	  }  
	}
	
	closesocket(clientSocket);
	WSACleanup();
	return 0;
}

See? You don't need to know the ip and port of the client in the whole process of socket programming at the code level. The following protocol stack will detect it by itself. But socket is actually to use the client's ip and port to uniquely determine a socket.