Answer:
a. A socket is a kind of opening.
b. A socket represents one endpoint of a network connection.
c. A program uses a socket to communicate with another program over the network.
d. Data written by a program to the socket at one end of the connection is transmitted to the socket on the other end of the connection, where it can be read by the program at that end.
Step-by-step explanation:
A socket is an endpoint in the network node of a computer network that serves the role of sending and receiving data written by a program across the network. The application programming interface specifies the attributes of a socket, through the socket descriptor. The socket address serves the purpose of making the socket identifiable by other hosts.
The socket address consists of the transport protocol, IP address, and port number. Just like a port serves as the endpoint in hardware, so does the socket also function as an endpoint in a network connection.