Computers date back centuries. Not the computers we know today - before them we had unreliable valves, and before that, complex hand-turned mechanical computers, and even before that it was a human's job to calculate Numbers. The first computers were very different from what we know today. today - they were people! The term “computer” meant “one who calculates”. It was the tedious work of calculating difficult mathematical equations. The problem was that these computers were human and humans make mistakes. In 1821, Charles Babbage looked at a sheet of mathematical equations. Seeing mistake after mistake, he decided what he needed was a machine – a computer – to do it for him. Such a machine would not make human errors. Babbage designed a mechanical device called the Difference Engine, and a section of the machine was built. Unfortunately, Babbage's investors couldn't see the progress he was making and cut funding. The difference engine was never completed. However, Charles Babbage had paved the way for future developments in this new technological field. The vacuum tube was invented in 1907. It propelled the electronics industry into the future, enabling inventions such as the radio. These vacuum tubes were huge, unreliable, and required a lot of power. However, used as switches, they made electronic computing possible. Valves were a key part of the first programmable computer, Colossus. During World War II, brilliant mathematicians set out to decipher the codes sent by the Nazis. It took months to crack the codes, and by then they were obsolete. So the British computer called Colossus was built to decipher the Enigma code sent by the Germans. Designed by Tommy Flowers, it was the ...... middle of paper ......the. The Osborne 1 from 1981 is widely considered the first true portable computer. Although very successful, it was bulky and could never be called a "portable computer" by today's standards. The NEC UltraLite of 1989 was considered the first "laptop"-style portable computer. Today, an average laptop costs between $500 and $1,000 and is common in homes, workplaces, and schools. As technology has evolved, new ways for devices to communicate with each other have had to be designed. No cables had to connect computers to the nearest power outlet or router. WiFi, or wireless local area network, was invented by the Australian CSIRO as a way to send large amounts of information very quickly. It is estimated that more than five billion devices use this technology (at the end of 2013) to connect to the Internet and transfer data quickly without being hampered by cables..