The purpose of communication is information.

The purpose of communication is information: exchange.

Knowledge expansion:

With the development of society, people's communication methods are no longer limited to traditional telephones and telegrams, because they can no longer meet the needs of large amounts of information, and communication means based on data are being widely used.

Data is a pre-agreed combination of numbers, letters and symbols with certain meanings, which can represent a wide range of contents.

In the computer network, data communication refers to the process of data transmission between computers and between computers and terminals.

The purpose of communication is to exchange information with each other. Before communication, we express the information we want to tell others as data, that is, data is the carrier of information, or data is the entity that carries information.

Data is transmitted by signals between different computers, so information, data and signals are very important concepts in data communication. What is the relationship between them?

Data contains information, which can be generated by interpreting the data. Formally speaking, data can be divided into analog data and digital data. Analog data will produce continuous values in a certain range, while digital data will produce discrete values.

In data communication, signal is the manifestation of electromagnetic wave during data transmission. Similar to the classification of data, signals can be divided into analog signals and digital signals. Analog signals are continuously changing electromagnetic waves, and digital signals are a series of voltage pulses.

A channel is a channel through which two communication parties transmit information based on the transmission medium, which is established on the communication line and its ancillary equipment. The concept of channel looks the same as the concept of transmission medium, but in fact they are not exactly the same, because a line composed of transmission medium may often contain multiple channels.

Channels can be divided into analog channels and digital channels. The channel for transmitting analog signals is called analog channel, and the channel for transmitting digital signals is called digital channel. Because there are many kinds of transmission media used at present, there are also differences in transmission characteristics among various transmission media.