Circuit switching is the type of switching where the entire capacity of a dedicated link is used.

Explanation:
Circuit switching is a method of establishing a dedicated communication path between two devices for the duration of a communication session. In this method, a dedicated physical circuit is established between the sender and the receiver, and the entire capacity of this circuit is reserved for their communication.

Key Points:
Here are some key points about circuit switching:

1. Full Capacity Utilization: In circuit switching, the entire capacity of the dedicated link is used for the duration of the communication session. This means that the link is fully utilized and dedicated solely to the two communicating devices.

2. Continuous Connection: Once the circuit is established, it remains connected throughout the communication session, even if there is no active transmission. This ensures that the connection is always available for immediate use.

3. Fixed Bandwidth: Since the entire capacity of the link is reserved for the communication session, the bandwidth remains fixed and guaranteed. This allows for predictable and consistent performance.

4. Real-time Applications: Circuit switching is commonly used for real-time applications such as voice and video communication, where a continuous and dedicated connection is required to maintain the quality of the transmission.

5. Resource Reservation: In circuit switching, resources are reserved in advance to establish the dedicated circuit. This can result in some inefficiencies, as resources may remain unused during periods of inactivity.

6. End-to-End Connection: Circuit switching establishes an end-to-end connection between the sender and the receiver, ensuring direct and exclusive communication between them.

In contrast to circuit switching, packet switching methods like datagram packet switching and virtual circuit packet switching do not utilize the entire capacity of a dedicated link. These methods divide the data into smaller packets and transmit them independently over the network, allowing for more efficient use of resources.

Conclusion:
Circuit switching is the type of switching where the entire capacity of a dedicated link is used. It is commonly used for real-time applications and provides a continuous and dedicated connection between the sender and the receiver.