When working in the computer industry,
it is important to understand the terms that are used. Whether reading
the specifications about a computer system, or talking with another
computer technician, there is a rather large dictionary of terms that
should be known. The technician needs to know the following
terminology:
- Bit – The smallest unit of data in a computer. A bit
can take the value of either one or zero, and it is the binary
format in which data is processed by computers.
- Byte – A byte is a unit of measurement that is
used to describe the size of a data file, the amount of space on a
disk or other storage medium, or the amount of data being sent over
a network. One byte consists of eight bits of data.
- Nibble – A nibble is half a byte or four bits.
- Kilobyte (KB) – A kilobyte is 1,024 (or approximately
1,000) bytes.
- Kilobytes per second (KBps) – KBps is a standard for the
measurement of the amount of data transferred over a network
connection. KBps is a data transfer rate of approximately 1,000
bytes per second.
- Kilobit (Kb) – A kilobit is 1,024 (or approximately
1,000) bits.
- Kilobits per second (Kbps) – This is a standard
measurement of the amount of data transferred over a network
connection. Kbps is a data transfer rate of approximately 1,000
bits per second.
- Megabyte (MB) – A megabyte is 1,048,576 bytes (or
approximately 1,000,000 bytes).
- Megabytes per second (MBps) – This is a standard for
the measurement of the amount of data transferred over a network
connection. MBps is a data transfer rate of approximately
1,000,000 bytes per second.
- Megabits per second (Mbps)
–
This is a standard for the measurement of the amount of data
transferred over a network connection. Mbps is a data transfer rate
of approximately 1,000,000 bits per second.
Note: A common error is confusing KB with Kb and MB with Mb.
Note that a capital B indicates bytes while a lower case b indicates
bits. Similarly, multipliers greater than one are capitalized and
multipliers less than one are lower case. For example, M=1,000,000
and m=0.001. Remember to do the proper calculations when comparing
transmission speeds that are measured in KB with those measured in
Kb. For example, modem software usually shows the connection speed
in kilobits per second (for example, 45 Kbps). However, popular
browsers display file-download speeds in kilobytes per second,
meaning with a 45 Kbps connection, the download speed would be a
maximum of 5.76 KBps. In practice, this download speed cannot be
reached because of other factors consuming bandwidth at the same
time.
Hertz (Hz) – Hertz is a unit of measurement of frequency.
It is the rate of change in the state or cycle in a sound wave,
alternating current, or other cyclical waveform. Hertz is synonymous
with cycles per second and it is used to describe the speed of a
computer microprocessor.
Megahertz (MHz) – One million cycles per second.
This is a common measurement of the speed of a processing chip.
Gigahertz (GHz) – One billion (1,000,000,000) cycles per second. This
is a common measurement of the speed of a processing chip.
Note: PC processors are getting faster all the time. The
microprocessors used on PCs in the 1980s typically ran under 10 MHz
(the original IBM PC was 4.77 MHz). In the start of the year 2000,
PC processors approached the speed of 1 GHz.
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