Analog signals are continuous where digital signals are discrete. Anolog signals are continuously varying where digital signals are based on 0's and 1's (or as often said------- on's and off's). As an analogy, consider a light switch that is either on or off (digital) and a dimmer switch (analog) that allows you to vary the light in different degrees of brightness. As another analogy, consider a clock in which the second hand smoothly circles the clock face (analog) versus another clock in which the second hand jumps as each second passes (digital). Digital computers work with a series of 0's and 1's to represent letters, symbols, and numbers. In addition, numbers are represented by using the binary code (where only 0's and 1's are used).Number Binary equivalent
1----------------------------- -----------------1
2----------------------------- ----------------10
3----------------------------- ----------------11
4----------------------------- ---------------100
5----------------------------- ---------------101
6----------------------------- ---------------110
7----------------------------- ---------------111
8----------------------------- --------------1000
and so on. So each number (that we are accustomed to, such as 5) is represented by 0's and 1's. Morse code uses dits (or dots) and dashes. Digital signals are similar to Morse code. The signal is either a dit or a dash for Morse code and it is either a 0 or 1 for digital. A series of these dits and dashes might represent SOS to a navy radio man, and a series of 0's and 1's might represent the question mark to a computer.
When an e-mail is sent that says "Hello Joe", Hello Joe doesn't mysteriously appear on Joe's computer. What is sent through the phone line is a series of 0's and 1's and Joe's computer "interprets" these into the words Hello Joe. If you type the letter A into your computer, it converts this A into 01000001. This 01000001 goes to Joe's computer and his computer interprets it as A. Each 0 or 1 is "bit" and the series of eight 0's and 1's is a byte. Well, that is about as simple as it gets and about as simple as I can state it.
It is interesting to see that the differences between analog cable connections and digital connections shows us much more about how technology is designed than you could ever imagine. The mere fact that digital signals work more like Morse Code shows us that history really does repeat itself and many times the simpler technologies are often the more dominant and efficient ones.
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