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What
is…?
Here are some definitions of IT terms that should
help you master the basics.
Computer Systems
Monitor or Screen
Keyboard and Mouse
Base Unit
Power Supply Unit (PSU)
Motherboard (mobo)
Processor (CPU)
Memory (RAM)
Hard Disk Drive (HDD)
Cards (Sound, graphics etc)
DVD, CD, Zip and Floppy Disk Drives
Databases
Internet and Email
Information
Communication
Buying and Booking Online
Networks
Cable Connection
Wireless
Benefits
Printers
Inkjet
Laser
Software
Commercial
Bespoke
Operating Systems
Computer Systems
Everyone knows what a computer is and the kinds of things that can
be done with them. Here is some basic information on the most common
components which you may have to consider.
Monitor or Screen
There are two basic types, CRT (Cathode Ray Tube) which are very
deep behind the screen and take up a considerable amount of desk
space, and Flat Panel monitors. CRT monitors give a more detailed
and smoother moving image, use more electrical power, and are the
cheaper of the two. The actual screen of a CRT is traditionally
slightly curved, but you can get pure flat ones.
Flat Panel monitors use up much less space (especially useful on
reception counters), look much nicer and consume less power, but
are more expensive, roughly three to four times more expensive.
Although almost as good as CRT monitors, the lesser image quality
makes them not the best choice for professional image editing or
high-end graphical applications.
Keyboard and Mouse
Increasingly common these days are the wireless types, which give
a tidier and more convenient workspace.
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The Base Unit or "Big Metal Box"
The Base Unit is the large box into which you can insert disks,
sometimes called a 'processor' because it mostly contains all the
components which do all the processing and storing of information.
It is not often referred to as a processor anymore since this can
be confused with the other type of processor (microchip), so the
most common term is Base Unit. It contains all the following components:
- Power supply unit (PSU)
- Motherboard (mobo)
- Processor (CPU)
- Memory (RAM)
- Hard Disk Drive (HDD)
- Cards (Sound, graphics etc)
- DVD, CD, Zip and Floppy Disk Drives
These components are all very modular in that each have their own
specific purpose and each component can be physically attached or
detached from the rest of the system. This makes replacing or adding
components very practical.
Power Supply Unit (PSU)
This is another metal box which transforms the 240 volt mains voltage
to 12 volts which most computer components use. Since the transformer
generates considerable heat, it also contains a cooling fan. The
most common power rating is 300 Watt, with 400 Watt PSU's being
recommended for the newest and higher performing machines.
Motherboard
This is a large circuit board which all other components plug into.
It contains the channels of communication for all the other components,
as well as some microchips to control the initial startup phase
and initialisation of the other components. The choice of this component
is critical if planning for expansion and later upgrades.
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Processor
This is the microchip which processes all the millions of logical
instructions every second, it is the 'brain' of the computer. Most
measure about 2" square and are flat with three to four hundred
gold contact pins sticking out of the bottom which plug into a socket
in the motherboard. The 'speed' at which it operates is given in
Megahertz (Mhz, millions of cycles per second), or Gigahertz (Ghz).
1 GHz is a thousand megahertz. The current (March 2002) maximum
available is 2.2 GHz.
Current retail prices, inc VAT, for just the CPU chip:
800 MHz = £50
1.4 GHz = £100
1.7 GHz = £245
2.0 GHz = £355
2.2Ghz = £600+
However, the speed of the CPU is not the only factor in the overall
speed of the computer as the CPU may end up 'waiting' on other slower
components. The other two main factors are Memory and Hard Disk
Drive.
Memory
This is the computers temporary, electronic memory, and is used
in much the same way as human memory. This type of electronic memory
is very fast, and hence is used by the processor to keep information
which needs to be readily available for the immediate task in hand.
It is measured in Megabytes (Mb), and is commonly found in amounts
of 64Mb to 512 Mb in most computers. The more a computer has, the
bigger chunks of information it can process and 'shuffle' around,
but remember, memory or RAM is only temporary and is 'flushed' when
the computer is switched off. There are many types of memory, differing
mainly in speed.
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Hard Disk Drive
This is used for long term storage of files. Both files you have
created, like letters, or graphics, and also files which contain
instruction sets (programs) which tell the computer how to perform
your requests. The size of a hard drive is measured in Gigabytes
(Gb), usually 20 to 40 Gb. As well as its size, the other very significant
factor is its speed. There are two types of speed. One is how fast
the disk spins, given in revolutions per minute (rpm), commonly
4200, 5200, 7200 rpm. The other is 'seek time', i.e. the time taken
for the drive to locate a piece of information and start accessing
it. This is commonly 12 - 20 milliseconds (ms). These two speed
factors will make a noticeable difference in overall system performance.
Cards
The components which provide things like screen image, the sound,
the network connection commonly come in form of a circuit board
which again plugs into the motherboard. The function of the card
is given in its name. Video or graphics cards process the image
signal for the screen and hence are critical in graphic-intensive
applications like video editing or video games. The common slot
type these cards use to connect to the motherboard is called a PCI
slot. Video, sound, network and modem cards can also be built-in
to the motherboard, and are referred to as 'on-board'.
DVD, CD, Zip and Floppy Disk Drives
These drives are used to read data from and write data to disks
which are inserted into their respective drives. They offer a convenient
way of transferring data or programs from one computer to another.
It has always been possible to read from, as well as write to,
zip disks and floppy disks. Initially, DVD's and CD's were 'read
only', you could only read from them and not write anything to them.
But now you can write to both DVD's and CD's, but you will need
special 'recording' drives and special re-writable disks.
Disk Capacity:
DVD = 2 Gb, or 4 Gb if double sided.
CD = 700 Mb
Zip = 100 Mb, 250Mb or 1 Gb
Floppies = 1.4 Mb
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Databases
In most small businesses, the main function of computers is to process
information. To view customer information, to store orders or bookings,
to process invoices and stock reports from the order information,
to produce sales reports from the invoices etc. A database is a
very efficient way of storing all that information on a computer.
When you have it stored in this way, then it is possible to view
and process that information in exactly the way you want. For example,
you can choose exactly what information you want to store about
your customers, you can choose what information will be included
in your invoices and your reports, and how it is laid out. You really
can have complete control over, and a clear insight to that information,
which is a very powerful tool.
Internet and Email
The internet is a global network of computers. When your computer
is connected to the internet, it is part of that network, and it
can access that network. If you're used to a "dialling up"
to the internet from home, now it makes more sense to pay a little
extra for an "always on" and high speed internet connection.
There are three main ways in which the internet can be useful to
your business:-
Information
Communication
Buying
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Information
As a source of information, the internet is virtually limitless.
Here are just a few kinds of information that may be useful to your
business.
- Viewing websites of other companies, trade organisations and
the government websites like Inland Revenue, Health and Safety
etc.
- Product information and Reviews
- Business directories
- Research and Reference information
- Statistics
- Stock prices, Exchange rates
- News and Weather
- Maps and Directions
- Parcel tracking
- Advice
Communication
The main method of communication the internet offers is email. This
is very simple, might as well be instant and the cost is almost
negligible. But there are other methods of communication offered
by the internet, all at the same speed and low cost.
- Video conferencing across the globe
- Sending / receiving files
- Instant chat messaging
- Discussion groups or web communities
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Buying and Booking
Many of your suppliers will have their own websites, with online
catalogues and technical specifications etc. You can order stock
online without having to print out a fax and feed it through the
fax machine, nor would you have to meticulously read your order
over the phone.
You can also make travel and hotel bookings online, research trade
seminars and exhibitions online.
Having this limitless and largely free resource at your fingertips
really will change the way you work, and you will notice the absence
of those frustrating moments wondering where to find that piece
of information.
Networks
A network is the connecting together of two or more computers for
the purpose of communication and sharing. Both the methods of connection
will require a network card in each of the computers:
Cable Connection
Computers are most commonly linked by physical cabling which is
cheap to install, fast enough and very reliable. It can be inconvenient
when moving computers around, and depending on your office size
and layout may carry the expense of running cabling through your
building.
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Wireless
A recent yet affordable development is that of the wireless network.
This is quicker and easier to install, more flexible and easily
expanded. Mobile computing devices like laptops and pocket PCs can
be moved freely around the building while maintaining a connection
to the company network and internet.
Benefits
The connecting together of computers gives the following advantages.
- Sharing one printer/scanner/fax etc between multiple computers
- Sharing one Internet connection amongst several computers
- Internal e-mail and other instant messaging services
- Shared calendars
- Access any file from any computer while controlling who has
access to which files
- Store all files on a single system for increased security and
convenient backups
- With a wireless network, mobile computing devices like laptops
and pocket PCs can be moved freely around the building while maintaining
a connection to the company network, internet and email
- Centralised Storage and Processing
A common configuration is to have one special high performance
computer on the network with large storage capacity and fast processors.
This computer would be called a "server". It is used to
store everybody's files in a common area and also to serve them
with additional centralised and synchronised computing power which
relieves the work load on their own processors and ensures the same
information is available to everyone. Configuring applications and
performing backups can be done from a single location.
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Printers
Inkjet
Inkjet printers are cheap (under £50 - £150) and small,
and can print in colour. However, they are quite slow, can be noisy,
consume a lot of ink, and print quality is not as good as with a
laser. They print by 'squirting' almost microscopic dots of wet
ink on to the page. Inkjet printers which print on A3 paper are
also available, and relatively cheaply. Generally good for small
run graphic work like leaflets and posters, and small volumes of
office printing.
Laser printers
Starting at around £160, monochrome (black and grey shades
only) laser printers give perfect quality printing and are very
fast, cheap to run and suitable for high volume printing. The high
end laser printers can print in full colour at high resolution and
prices start at just over £1,000.
Software
For each different type of task you wish to perform with your computer,
like word processing, spreadsheets, or drawing, there will be a
computer program to do the job, which usually comes on a compact
disk. Other terms for programs are "software", or "applications".
Before you can use the program, the files on the disk need to be
transferred to your computer. This is called "installing software".
Once this is done, the program can be started anytime simply by
clicking on a button.
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Commercial
There is software available for almost any task you may wish to
perform with a computer, and there are several different "brands"
of software for any one of those tasks like word processing or drawing.
Also, some programs are basic, while others are very advanced.
For the "standard" computing tasks which are common throughout
most businesses, like word processing, spreadsheets and email, most
people use the same software, made by Microsoft Corporation. They
offer a "package" of the common programs which is called
Office. This "bundle" includes word processing, spreadsheet,
database, presentation and email programs. Although each individual
will use the programs for different things, they are so rich in
features they can accommodate the demands of all these different
users.
Bespoke
For other not so standard computing tasks, like a hotel's reservations
and billing, while you can be pretty sure there is an off the shelf
program which will do the job, since every hotel is very different
and works differently with different management styles, you're not
likely to find one which 'fits' as well as you would like it to.
As with databases, you can have your own program custom designed
and developed for your particular operation, and it can be designed
to accommodate the nuances and specialties of your business.
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Operating Systems
Examples of desktop computer operating systems are:
The Microsoft Windows family: Windows 98, ME, NT, 2000, XP.
The Apple Macintosh series: Mac OS7, 8 or 9.
UNIX and Linux
There are several others for different types of computers, including
servers and pocket computers.
These are very different from the application programs discussed
above. Although they are the same in that they are both programs
or 'instruction sets' which tell the computer how to perform tasks,
the difference with operating systems is that their task is to manage
and control the hardware devices within the computer and also to
manage the application programs.
Every computer requires an operating system before it can do anything
else. The application programs are then installed onto the operating
system. For example, a computer can have Microsoft Windows XP as
the operating system, and it can run Microsoft Office 2000.
The different operating systems have all evolved from very different
beginnings, with different features, benefits and suitabilities.
But generally, although they may operate differently behind the
scenes, the newer desktop operating systems are heading in the same
direction when it comes to general user experience.
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