What is end-to-end and point-to-point?

Http://www.cnitblog.com/guopingleee/archive/2007/10/14/34843.html

End-to-end and point-to-point are for the relationship between devices transmitted over the network. End-to-End transmission refers to the establishment of a link between two devices through a variety of switching devices before data transmission, just as they are directly connected. After the link is established, the sender can send data until the data is sent. The receiver confirms that the data is successfully received. The point-to-point system refers to the device that the sender transmits data directly to. When appropriate, the device transmits the data to the next device directly connected to the device, data is transmitted to the receiving end through a directly connected device.
The advantage of end-to-end transmission is that after the link is established, the sender knows that the receiving device will be able to receive the data and does not need to store and forward the data when it passes through the intermediate switching device. Therefore, the transmission delay is small. The disadvantage of end-to-end transmission is that the device at the sender must participate in the transmission until the receiver receives the data. If the entire transmission delay is long, it will cause a great waste on the device at the sending end. Another disadvantage of end-to-end transmission is that if the receiving device is shut down or fails, end-to-end transmission is impossible.
The advantage of point-to-point transmission is that after the sender device sends data, its task has been completed and does not need to participate in the entire transmission process. This will not waste the resources of the sender device. In addition, even if the receiver device shuts down or fails, point-to-point transmission can also use the storage and forwarding technology for buffering. The disadvantage of point-to-point transmission is that after sending data, the sender does not know whether or when the receiver can receive the data.
In different layers of a network system, end-to-end transmission or point-to-point transmission may be used. For example, point-to-point transmission is adopted for Internet networks, IP addresses and the following layers, and end-to-end transmission is adopted for layer-4 and above.