On the Net

with Alex Clarke

Understanding Computers part II

Continuing our glossary of terms from last week, this week we look at some more of the things that make a computer tick.

CPU

The Central Processing Unit is the brain or engine of your computer. The main measure of a processor is its speed in Hertz or cycles per second. If you think of a processor as a clock, 1 GHz means the clock ticks one billion times a second.

There are many different types of processor available. The most common ones are the intel-compatible (aka "x86") chips, such as the Intel Pentium and AMD Athlon processors. Apple's Macintosh computers use IBM/Motorola PowerPC processors, which have a completely different architecture to the x86 type.

Another important feature is bit-width. Until recently all common processors were 32 bits wide. 64 bit processors are able to handle twice as much information in each cycle, effectively doubling their performance. The Apple G5 and AMD Athlon64 are 64 bit CPUs.

Operating System

The operating system is the personality of a computer. Many people don't even consider their options in this area - they just buy a PC. If they do, their OS options are between Windows and the various flavours of Linux. Hobbyists should opt for Linux, most everyone else for Windows XP - which comes preinstalled on most PCs anyway.

I have written a lot about operating systems in my columns, and many people would have guessed by now that I am a Mac partisan. Apple do things differently than the rest of the industry, and the different OS is the main advantage Apple offers.

The Mac is not a PC - it doesn't run Microsoft Windows natively, although if you really need to, you can. A Mac is a different type of computer - yet they work with almost all PC peripherals, such as printers, scanners, digital cameras, and so on. The main difference is software. Macs run different software because they have a different CPU from PCs.

The Mac's operating system is called, appropriately enough, Mac OS X (that's a Roman X - ie 10). It is becoming a very popular choice for most kinds of computer users due to its unique combination of simplicity and power. Most of the software that people need, such as mail, web browsing, photo album, jukebox, movie editing, and more is provided for free with the OS and integrates perfectly.

There is a huge amount of freeware and shareware available, as well as thousands of popular commercial programs in all categories.

Broadband

Broadband is just fast internet - up to 50 times faster than a dial-up connection. Broadband prices have recently crashed and it is now within the reach of most people who could afford a dial-up connection... if you live within 4kms of a modern telephone exchange. There are many different deals available, so shop around to find the one that best suits you. The big companies don't necessarily have the best pricing.

Internet networking

The internet is the network of networks. Essentially it is a protocol, or a common language, so different types of computers can communicate with each other across wires or wirelessly. This protocol is known (poetically) as TCP/IP. Each computer has an IP address, like a phone number, which identifies it uniquely to all other computers.

World Wide Web

The www lives on top of the internet - it is a protocol called HTTP that uses TCP/IP as its base. HyperText Transfer Protocol allows pages of text and images to be sent from a server to a browser like Internet Explorer or Firefox.

DNS

A Domain Name Server is a server that lives on the internet, and is usually provided by your ISP. It is like a telephone directory - it converts machine IP addresses into human terms - for example, 203.12.160.35 into "www.tpg.com.au".

USB

Universal Serial Bus is Intel's high-speed standard for connecting peripherals to a computer. Nowadays almost all printers, scanners, mice and keyboards use this standard. The newer USB 2.0 allows devices to communicate at 200 MB per second. All Macs made since 1998, and all PCs since 2001, have USB connectors.

HotNews

File sharers be warned! The US Justice Department is planning a major new offensive against software, music and movie piracy to be styled on the war against drugs and terror. US Attorney General Richard Ashcroft announced the legal offensive on October 12. Dan Glickman, president of the Motion Picture Association of America, said, "Peer-to-peer networks that facilitate illegal file sharing are some of the most dangerous threats to copyright ownership today."

HotSites - Kids Sites

www.bubblegumclub.com

Ishtar Welstead (13) recommends this site for R&R between homework and bed-time. Plenty of puzzles, games and brain teasers, with an excellent selection of Flash games. Make sure you have the latest Flash Player.

www.abc.net.au/children

For the younger kids, The Playground combines education and fun with some familiar characters to make an excellent and diverting site.

www.ajkids.com

If you worry about what your kids may find by accident on the net, why not bookmark a child-friendly search engine for them? Ask Jeeves Kids filters all its search results, ensuring they are appropriate for all age groups.

• Chris Goh is taking a holiday and Alex will be writing on the internet and computers over the coming weeks.