tailieunhanh - Networking: A Beginner’s Guide Fifth Edition- P7

Networking: A Beginner’s Guide Fifth Edition- P7:I have run into many people over the years who have gained good even impressive working knowledge of PCs, operating systems, applications, and common problems and solutions. Many of these people are wizards with desktop computers. | 12 Networking A Beginner s Guide You don t need to have a . in computer science to be an effective networking person but you do need to understand some rudiments of the subject. This chapter discusses basic computer terminology and knowledge that you should possess to make the information in the rest of the book more useful and understandable. If you ve been working with computers for a while and especially if you have training or experience as a computer programmer you might not need to read this chapter in detail. However it is a good idea to at least skim it to make sure that you understand these subjects thoroughly. Bits Nibbles and Bytes Most people know that computers at their most fundamental level work entirely using only 1s and 0s for numbers. Each of these numbers whether it is a 0 or 1 is called a bit which is short for binary digit. String eight bits together and you have a byte string about 1 000 bits together and you have a kilobit or you can string about 1 000 bytes together for a kilobyte. A rarely used unit is composed of four bits strung together called a nibble. Remember this for when you play Jeopardy Understanding Binary Numbers Before you learn about binary numbers it s useful to recall a few things about the numbering system that people use on a daily basis. This is called the decimal numbering system or alternatively the base-10 numbering system. The decimal numbering system is built using ten different symbols each of which represents a quantity from zero to nine. Therefore ten possible digits can be used 0 through 9. The base-10 numbering system gets its name from the fact that only ten digits are possible in the system. An important part of any numbering system is the use of positions in which the numerical symbols can be placed. Each position confers a different quantity to the number being represented in that position. Therefore the number 10 in the decimal system represents the quantity ten. There is a 1 in the tens position and a