The first information technology revolution was the use of language. It happened about 35,000 to 50,000 years ago. The second information technology revolution is the creation of words. Around 3500 BC, the third revolution of information technology appeared in words, which was the invention of printing. Around 1040, China began to use movable type printing technology (Europeans began to use printing technology in 145 1 year). The fourth information revolution was the invention and popularization of telegraph, telephone, radio and television. 1837, American Morse invented the world's first wired telegraph. The telegraph uses the principle of electromagnetic induction (when current passes, the electromagnet is magnetic, and when no current passes, the electromagnet is non-magnetic) to make the pen connected to the electromagnet rotate, thus drawing the symbols of points and lines on the paper tape. The proper combination of these symbols (called Morse code) can represent all the letters, so that these words can be transmitted through wires. 1844 On May 24th, the first telegram in human history was transmitted from the US Capitol to Baltimore, 40 miles away. Maxwell, a famous British physicist, published a paper (electricity and magnetism) in 1864, predicting the existence of electromagnetic waves. On March 1876 and March 10, Bell, an American, had a phone call with his assistant. 1895, Russian popov and Italian Marconi successfully conducted radio communication experiments respectively. The movie came out on 1894. 1925 TV was first broadcast in Britain. The fifth information technology revolution began in the 1960s, which was marked by the popularization and application of electronic computers and the organic combination of computers and modern communication technologies.