Computer Review

What does BIOS mean ?
BIOS - Basic Input Output System
The CPU in a PC needs a way of communicating with the many different hardware devices that are installed, each hardware device has its own special BIOS software which allows for this communication.
The BIOS contains special software instructions that enable the CPU to communicate with and control devices, it is usually stored in ROM and can be either built-in to the motherboard or on the device itself.
The main BIOS in a system is stored inside a microchip on your motherboard and is the first piece of software your computer runs when you (boot up) turn it on.
It uses the information stored in the CMOS memory for configuration purposes.
A Flash BIOS can be updated with new information and many motherboard manufacturers publish updates for their respective BIOS on their websites.

What does ACPI mean ?
ACPI - Advanced Configuration Power Interface
ACPI (Advanced Configuration Power Interface) refers to a Power Management specification developed by Intel, Microsoft and Toshiba. The specification allows an operating system to control the power distribution to peripherals such as hard drives, it was originally intended for laptops/notebooks where power saving is vital.
Since Windows 98, ACPI has replaced the older APM (Advanced Power Management) specification (used in Windows 95).
ACPI allows the operating system to communicate with the computer's BIOS and instruct the BIOS to power down peripherals, for instance when your computer goes into hibernation mode, the operating system is using the ACPI specification to control the power to the internal components.

What is Binary - Base 2 ?
Binary is a number system used by digital devices like computers, cd players, etc.
Binary is Base 2 unlike our counting system decimal which is Base 10 (denary).
In other words, Binary has only 2 different numerals (0 and 1), unlike Decimal which has 10 numerals (0,1,2,3,4,5,6,7,8 and 9).
Here is an example of a binary number: 10011100
As you can see it is simply a bunch of zeroes and ones, there are 8 numerals in all which make this an 8 bit binary number, bit is short for Binary Digit, and each numeral is classed as a bit.
The bit on the far right (in this case a zero) is known as the Least significant bit (LSB), and the bit on the far left (in this case a 1) is known as the Most significant bit (MSB)

notations used in digital systems:
4 bits = Nibble
8 bits = Byte
16 bits = Word
32 bits = Double word
64 bits = Quad Word (or paragraph) When writing binary numbers you will need to signify that the number is binary (base 2),
for example take the value 101, as it is written it would be hard to work out whether it is a binary or decimal (denary) value, to get around this problem it is common to denote the base to which the number belongs by writing the base value with the number, for example:

1012 is a binary number and 10110 is a decimal (denary) value.

Once we know the base then it is easy to work out the value, for example:

1012 = 1*22 + 0*21 + 1*20 = 5 (five)

10110 = 1*102 + 0*101 + 1*100 = 101 (one hundred and one)

One other thing about binary numbers is that it is common to signify a negative binary value by placing a 1 (one) at the left hand side (most significant bit) of the value, this is called a sign bit.

What does ADSL/DSL mean ?
ADSL - Asymmetric Digital Subscribers Line
Sometimes refered to as Broadband, ADSL is a connection available from Telecom companies using existing lines with fast download & upload speeds.
It works by splitting your phone line signal into two seperate channels, one for normal voice usage and the other for data usage, this is achieved by placing a splitter on the existing phone line to enable multi-frequency communication.
It can reach speeds of up to 9Mbit per second for downloading and currently up to 640Kbits per second upload speed.
Another advantage of having an ADSL line is not missing calls while you're online, as both voice and data can be transferred at the same time.

What does Bandwidth mean ?
In computing
Bandwidth refers to the capacity of a communications line/channel to transmit/receive information and is measured in bits, bytes, kilobytes, megabytes and gigabytes.

Internet Service Providers
Bandwidth (when specified by an ISP) is the monthly quota of data that you are allowed to upload and download with your internet connection, your monthly bandwidth allowance will (usually) be measured in Megabytes or Gigabytes, the amount of bandwidth you need depends on how you intend to use the internet.
For example, if you will be using the internet just to view websites, then you won't need as much bandwidth as someone who is downloading music and video for the same amount of hours.
note: one Megabyte (MB) = 1024 Kilobytes (KB).
* The average webpage is around 50KB (kilobytes) including images
* The average MP3 audio file is around 4MB (Megabyte)
So you would use the same amount of bandwidth to download one MP3 audio file as you would to view eighty one webpages (50Kb) on the internet.
As you can see it depends greatly on what you are using your internet connection for as to how much bandwidth you will need.

Web Hosting companies
When in the context of web hosting companies it refers to how much traffic a web hosting company will allow each month.

What is E-Mail ?
Email - Electronic Mail
This is a system used by computers to send and receive messages over the internet, when you send an email and likewise when someone sends you an email, the message will remain on the server (your email providers computer) until it is read and deleted, in other words you don't have to be connected to the internet to read an email unlike chat. For more information click here to see our beginner's guide.

 What does DVD mean ?
 DVD - Digital Versatile Disc (Digital Video Disc)
A DVD (digital versatile disc) is similar to an audio CD, but has a storage capacity far greater (up to 17Gb) and a faster access time (up to 1.3MBps) than a standard CD-ROM.
Due to the bigger capacity, faster access time and the use of MPEG compression, DVDs are commonly used as a medium for digital video.
Some DVDs can store data on both sides of the disc (4.7Gb per side / 133 mins of video with sound). Double sided, dual layer discs can hold up to 17Gb of data.
DVD Writers (DVD-R/RW) allow the home user to back up any old video, or create back-up copies of DVDs.
DVD Writers are often advertised as 4X-4X-12X, this means it will burn (write) at 4X, ReWrite (write again over an existing rewritable DVD) at 4X, and read at 12X the normal DVD speed.

What is DRAM ?
DRAM - Dynamic Random Access Memory
A type of memory (RAM) widely used in today's PCs. DRAM works differently to SDRAM as it needs to be refreshed to continue holding the data, this means a slight loss of speed as the memory refreshes itself with a pulse of current to each of its cells.

What is DOS ?
DOS - Disk Operating System
This is a system that software uses to utilise the disk drives in your computer. See also MS-DOS.
IBM® first created DOS® for the series 700 computers years ago, then Microsoft® developed their own version called MS-DOS®, over the years DOS has become outdated due to it's limited capabilities, although Windows® still shipped with MS-DOS® until the recent XP version.

What does CPU mean ?
CPU - Central Processing Unit
his refers to the processor (or brain) in your PC system:
Its common components are as follows:
* CU - Control Unit, this sequences, controls and times the other functions of the CPU.
* ALU - Arithmetic Logic Unit, this carries out simple mathematical equations on the binary data stored inside the data registers.
* Registers - these are temporary memory locations which hold binary data and store the results of ALU calculations, there are also memory address registers which as the name suggests hold data concerning where in the memory certain instructions and data is held.
* BUS - this carries data between the memory and registers.

What is Coprocessor ?
Coprocessor Co-processor
This device is normally used to calculate complicated mathematics such as precision calculations, logarithms & trigonometric functions. It is normally stored inside the main processor (CPU), in the early processors it used to be a totally different chip housed on the motherboard, then, since, the 80486DX it has been integrated inside the main CPU casing. It was inside the 80486SX range aswell but was disabled.

What does cookie mean ?
Cookies are small text files that are placed on your computer by websites for various different reasons. For instance Yahoo use cookies for reasons such as storing your preferences for Yahoo related services, and to access certain information when you sign in to a personalised service such as My Yahoo.
Other websites will often use cookies for identifying purposes, demographic statistics and also when you are shopping online to remember what you have in your basket.

What is CODEC ?
CODEC - COmpressor / DECompressor
CODEC in the context of computing is an acronym for COmpressor/DECompressor and refers to a small piece of code (program) which is used to compress and decompress data, you will normally come across these when using Audio and Video. You may be prompted during internet use to download a CODEC if you visit a site that requires a certain CODEC not already installed on your PC.

What is CMOS ?
CMOS - Complimentary Metal Oxide Semiconductor
When in the context of computing CMOS refers to a chip that stores information about your PC including the time, date and configuration data, this technology is used due to the low power consumption.
The CMOS device is backed up by a battery to retain the information when the system is switched off.
The information (typically 64 Bytes) in the CMOS device is accessed by the BIOS when the machine is booted up (turned on), the CMOS settings (information) can be changed by the user by the way of a setup program usually accessed with a key sequence when the machine is first booted.
Different systems use different key sequences to access the CMOS settings (BIOS settings), you can find out the key sequence for your particular system from either the manual that came with your machine or your motherboard manual.

What is Chip ?
Chip - Microchip

When in the context of electronics/computing this refers to an integrated circuit, made up of logic gates, transistors, and passive components to make a device dedicated to a certain function, for instance a typical chip found in most households is the Digital to Analogue Converter found in audio CD players.

What is Microprocessor?

This little chip is the heart of a computer.
Often referred to as just the "processor," the microprocessor does all the computations like adding, subtracting, multiplying, and dividing. In PCs, the most popular microprocessor used is the Intel Pentium chip, whereas Macintosh computers use the PowerPC chip (developed by Motorola, IBM, and Apple).
The speed of a microprocessor is measured in megahertz, or cycles per second.
But higher megahertz doesn't always mean better performance.
Though a 600-MHz chip has a clock speed that is twice as fast as a 300-Mhz chip, it doesn't mean that the computer with the 600-Mhz chip will run twice as fast.
This is because the speed of a computer is also influenced by other factors, such as the efficiency of the processor, the bus architecture, the amount of memory available, and the software that is running on the computer.
Some processors can complete more operations per clock cycle than other processors, making them more efficient than other processors with higher clock speeds.
This is why the PowerPC chip is typically faster than Pentium chips at that are clocked at higher megahertz.

CD ROM - Compact Disc Read Only Memory
This is similar to an audio CD and works in much the same way but stores data instead of music. A typical data CD can store up to 700Mb, 486 times more information than a standard 1.44Mb 3.5" floppy disk.
A CD Writer (cd burner) can save data or audio to a special type of recordable CD (CDR or CDRW), this is an excellent way of backing up your data or creating audio CDs.
You will often see CD Writers advertised as 48X-12X-50X, this means it will burn (write) at 48X, ReWrite (write again over an existing rewritable CD) at 12X, and read at 50X the normal CD speed.
For instance a 48X CD Writer will write a CD 48 times faster than normal (74min audio CD in just under 2 mins).
CDR (Compact Disc-Recordable) refers to a recordable CD ideal for backing up data, although normal CDRs can be used to create audio CDs, there are special audio CDRs which offer a higher quality of audio reproduction.
CDRW (Compact Disc Re-Writable) refers to a recordable CD which allows the data to be overwritten numerous times (handy for daily back-ups).

What is a Cache ?
Pronounced "Cash" this usually comes in two forms, either disk cache or memory cache, the former being a space normally on a hard disk set aside by the computer/software to store information it thinks it will need again, for instance browsers use disk cache to store information from websites such as pictures and alike, this reduces the need for the modem to keep downloading the same data each time you visit a webpage. The latter can either utilise normal memory or special memory which has a faster access time that is used by the system to store information that is used frequently, it can also 'guess' what information the user may require next and loads this into the cache memory for faster access.

What is Browser ?
This is the program you use to surf the internet, i.e. Internet Explorer, Netscape Navigator, Opera etc. Different browsers render web pages slightly differently, for example some sites may require a certain browser to function correctly and some sites may not function at all with some browsers.

What is Ethernet ?
Ethernet - Networking
Refers to a standard of the LAN system, Ethernet supports up to 10Mbps per second transfer, a newer implementation of the Ethernet specification 100 Base-T supports up to 100Mbps.
The latest standard (Gigabit Ethernet) can support up to 1000Mbps (1 Gigabit).
Ethernets are common place in offices where file/device sharing is required.

FAT - File Allocation Table
FAT (File Allocation Table) refers to a data table that holds information about how and where files are stored on any one partition (for simplicity think of a partition as all the files on your hard drive).
For example, a single file on your hard drive may not be stored in one place, the file could be split up and stored in several different (physical) places (this is called fragmentation), the FAT keeps a record of where the different parts of the file are stored.
The FAT system does not duplicate critical data (as opposed to NTFS) so if a critical sector is lost then it can mean the loss of all data within the partition.
FAT16 was used in the first releases of Windows 95.
FAT32 is used by Windows 95 (later releases), Windows 98/98se and supported by Windows XP.