Richard Farrar's Blog

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How often have you been browsing the web when you suddenly see a little padlock symbol appear in the corner of your web browser? Well, this symbol indicates that you have entered a secure web page, but how secure is it and how does it all work?

Security is a big issue online. We’re constantly being bombarded by the media about online fraud, spam and all sorts of other nasties that we could encounter while surfing the web, almost to the point of becoming so paranoid that we won’t go online anymore.

However, there are technologies in place to try and make things a little safer. For example, whenever you enter your credit card details online, you have probably entered a special secure type of web page without realising. So what is this special type of web page, how do you know if you’re on one and how secure is it anyway?

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In stumbling around your computer’s operating system, or when setting up an internet router for your broadband access, you may have come across the term MAC address. It’s obviously pretty important for getting things talking on the internet, but what exactly is a MAC address?

Well, in computer terms, a MAC address certainly isn’t the address of your local fast food joint where you can order an oversized cheeseburger and large fries, but it is fundamental to the operation of your computer on a network.

So if you’d like to know a bit more about the ins and outs of a computer’s MAC address, rather than the contents of a McDonald’s deep fat fryer, then scroll down on your McMouse, or tap on your McKeyboard and read all about it.

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Whenever you fill in an online form, you are invariably confronted with a picture of horribly distorted words that you are asked to spell. Are these web hosts just needing a little extra help with their spelling, or is there something more subtle going on?

Filling in online forms nowadays can be a bit of a mission. Not content with forcing you to fill out pages of obscure questions about your first pet etc., before allowing you to hand over your hard earned cash to buy the website’s latest offering, web hosts are now also asking you to decipher increasingly cryptic pictures of words before allowing you to continue.

Is this just a global conspiracy to test the online world’s spelling abilities, or is there a deeper, more important meaning?

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While the term URL may not be familiar to everyone, the chances are that you use them everyday without knowing, as a URL is essentially just a web address. But what do all the different parts of a URL actually mean?

URLs are things we use every day in our general surfing of the web, but they are something that many of us will never stop to think about too much.

So partly in response to a request left in a comment from a reader, Joebunny, and partly as a prelude to a forthcoming post that will require a general understanding of URLs, I hope to explain, without going into too much detail, what a URL is all about.

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When people talk about MP3 files and the like, you often hear the term Bit Rate also mentioned, so what’s it all about?

Until the mid 1980s, commercially purchased music was always in analogue format, be it typically vinyl or cassette. In late 1982, the arrival of the now ubiquitous compact disc (CD), co-developed by Sony and Philips, changed all that and revolutionised how we listen to music.

Digitisation

In order to create digital recordings such as CDs, the conventional analogue audio first has to be digitised. The process of digitisation takes the original audio source and chops it up into lots of thin slices. Each slice represents the volume of the audio source for a particular point in time. A digital number then stores the volume level of this slice on the CD. Each slice, or sample as it’s actually called, represents the level of the audio for a mere 23µs (23 millionths of a second).

To reconstitute the audio track, all of these samples are stuck together and the volume level of each sample is sent out to your speakers every 23µs (in the case of CDs). It’s a bit like slicing a loaf of bread and then squeezing all of the slices of bread together again to make it look like the original loaf. Not perfect, but if you squint, you’d never know that difference. CDs are very similar, because the slices are so thin, you don’t know the difference.

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