1. Letter:
A tool for people who are far apart and have not met for the time being to exchange feelings and ideas with each other. Letters have a long history and people all over the world use them. Letters play an important role in the history of human communication. Today, mobile phones, telephones and computers are simple and fast communication tools all over the world, and some people are still willing to exchange information by mail. However, due to the arrival of the information age, the format of letters has become diversified, and they are no longer limited to the original classic format. Some of them don't even have an object, that is, they don't have lectures and argumentations from the recipients.
2. Telephone:
Remote communication equipment that can send and receive sound. As early as the eighteenth century, the word "telephone" was used in Europe to refer to microphones strung together with wires (cups strung together with wires) The telephone was attributed to Alexander Graham Bell. The principle of early telephone is that sound is a compound vibration in the air, which can be transmitted to solids and to conductive metals through electric pulses. ? Bell applied for the telephone patent in March 1876.
3. Computer:
A machine that processes data according to a series of instructions using electronic principles. Computer can be divided into two parts: software system and hardware system. The first universal computer, ENIAC, was born in February 1946.
People call a computer without any software installed as bare metal. With the development of science and technology, some new computers are constantly emerging: biological computers, photonic computers, quantum computers and so on. 1954 On May 24th, the transistor electronic computer was born.
4. TV:
Refers to the use of electronic technology and equipment to transmit moving images and audio signals, that is, TV receivers, which are also important broadcast and video communication tools. Television uses electricity to transmit moving visual images instantly. Similar to movies, TV uses the visual residual effect of human eyes to gradually change the still image frame by frame to form a visually moving image. The transmitter of the TV system converts every tiny part of the scene into electrical signals according to the brightness and chromaticity, and then transmits them in turn. At the receiving end, the brightness and chromaticity of each tiny part are displayed according to the corresponding geometric position to reproduce the whole original image. The scanning system and channel bandwidth of TV signals in different countries are not exactly the same. According to international radio consultative committee's suggestion, Latin letters are used to distinguish them.
5. advertising:
That is, the meaning of propaganda. Advertising is a kind of propaganda means to convey information to the public openly and widely through a certain form of media for a specific need. Advertising can be divided into broad sense and narrow sense. Broadly speaking, advertisements include non-economic advertisements and economic advertisements. Non-economic advertising refers to non-profit-making advertising, also known as effect advertising, such as various announcements, notices and statements of government administrative departments, social institutions and even individuals, whose main purpose is to promote sales; Advertising in a narrow sense only refers to economic advertising, also known as commercial advertising, which refers to advertising for profit. Usually, it is an important means to communicate information between commodity producers, operators and consumers, or an important form for enterprises to occupy the market, sell products and provide services, with the main purpose of expanding economic benefits.