Summary of Lesson 3:

   The lesson 3 is about the History of Computers, when did the computer was made and how it develops time by time. In ancient time, we have different numerals also known as the Egyptian numerals, it was used during 3400 B.C. but then Mathematicians discovered and invented new numerals that are used today, maybe because it is easier than the Egyptian numerals. In 500 B.C. Abacus was made for counting numbers... and until the latest computer used in counting was made. Many people develops new kinds of computers in counting, they have bright ideas. There's 4 different Generations of Computers, the different kinds of it is defined or group by the materials used. You will also know the different kinds of devices like USB, CDs, Web Camera and etc. with their uses too.
   There's different types of Computers like Supercomputers, Mainframe Computers and etc. In present time, Personal Computers are used because you can customize it by your own. We also use Laptops, they can be carried and can be bring anywhere, it is lighter and more developed. There are also Hand-held Computers like Palmtops, it is a kind of a computer that is big as your palm, there's also the Personal Digit Assistant (PDA) it is used in computing, telephone/fax and networking features.
   There are different ways on how to take care of your computer, this is written in Chapter 3, page 67, you can learn a lot of ways from here. You can also know what is the Proper Workstation Design, the different right positions while using the computer to avoid some illnesses. You will also know how to use computer if you are a beginner.