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Question: What is a modem?
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Answer: A modem is a piece of hardware that allows your computer to talk to
other devices over a regular phone line. |
A modem converts digital signals from your
computer into audible tones that can be transmitted over
regular analog phone lines. This conversion process is called
MOdulation. The modem on the other end then transfers those
same audible tones back (or DEModulates) into their original digital signals.
MOdulation and DEModulation is where the name MODEM comes from.
There are basically two different types of modems (internal-inside of the
computer and external-outside of the computer). Either type of modem works
technically the same way. One computer sends the information
digitally and then . . .
. . . the modem translates the digital signals into an analog signal. The analog
signal is transfers over the phone wires. The modem at the other end translates the
analog signal back into the original digital signal and sends that information to the computer.
There are actually signals going back and forth from the two computers to verify that
all of the information is correct. Kind-of-like repeating everything to make sure that
it is all heard correctly. The computers use a system of checksums to repeat
the information to save time.
Question: What is an analog signal?
Answer: Analog refers to adding signals to carrier waves, usually represented
as sine waves. These signals are not simply on or off. It is similar to a dimmer
on a light switch - not just on or off but many positions in between.
Question:What is a digital signals?
Answer: Digital signals are either ON or OFF and no in between - JUST like a
(regular) light switch for your room.
Question: What is a checksum?
Answer: Checksums are kind-of-like me giving you 100 numbers and you telling me the total. If the
total is correct, I assume that you heard all of the information correctly. It is a little
more complicated than that - but that is basically how it works. It
saves a considerable amount of time to verify information this way
rather than repeating everything.
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