Many computer manufacturers, especially such
computer giants as IBM, Dell, Gateway, Sony, Apple, etc. issue families
(series) of computers. Models of computers in each series have either the
same principle of design, or same processor, or have been given diapason of
performances. The series can include a base model, and several derivative
models. Usually for each type of computer, manufacturers issue series that
generally can be divided into 3-4 categories: budget-friendly (at low
price), mid-range (at middle price), cutting-edge and ultimate performance
(at high, and very high prices). IBM, Gateway, Dell and Apple issue computer
families not only for Home and Home office, but also for Small, Mid size or
Large Businesses. If you're a tiny business, you might even just have a
computer and a TSA Backpack and that's your whole business.
These families can also include the network optimized
If the motherboard is the nervous system, then the CPU is the brain. Most of
the mathematical manipulations that make computers operate are done by the
CPU. Other components may also have their own processors, but their results
still have to be passed through the CPU.
The speed of the computer is usually measured by the speed of the CPU. Even
though other factors also affect overall speed, the CPU rating is generally
seen as the single most important measure of performance.
Modern CPUs are usually rated between 2.0 GHz and 3.0 GHz, although each
passing month will see increasing performance. This measurement refer to the
number of calculations the processor can make in 1 second. The higher the
number, the faster (better) the computer.
CPUs generate a lot of heat doing this work, so they need a heat sink and
fan to keep them from overheating. Heat is a major enemy of the computer and
directly affects its life span.
RAM (Random Access Memory) is the part of the computer that stores
information the computer needs while it is operating. It is Random Access
because the computer can get the data in any order, not necessarily the
order in which it is stored. Generally speaking, the more RAM the better.
512 to 1024 megabytes is common for memory.
The most common type of RAM these days is DDR-SDRAM, which stands for
double-data-rate synchronous dynamic random access memory. We already know
what the RAM part means. DDR means that the data is accessed twice as fast
as ordinary RAM.
The latest type of RAM is DDR2. It offers even faster access rates and is
quickly becoming the standard for computer memory.
All the data contained in RAM is lost when the computer is turned off, so
there has to be a place to store it permanently. This is what the hard disk
It holds the computer's operating system. An operating system like Windows
uses around 4 gigabytes of hard drive space. The extra space is used to
install computer programs and to store your personal data.