As I understand it, a bit is a unit of information like a byte. Fair enough. So when something is described as 32 bit or 128 bit (like playstations for example) what does it mean? Is it about processing speed or what.

Processors are measured in hertz which I understand (a little), hard drives in rpm's but someone please explain the significance of bits.

An explanation would be much appreciated.

Another example: PGP offers 128 bit security. What the hell does that mean???

Cheers now

1 byte = 8 bits

AFAIK, 32bit CPUs can process 32 bit integers in one instruction and access 2^32 memory addresses in a single page. It does not describe the speed of the CPU but the capability.

Bits in encryption describes the length of the key. The larger the key, the more difficult it is to crack the key via brute force. Take note, however, that you cannot compare the security using bits between different encryption scheme. A 128 bit RC5 (symmetric) key, for example, is way more secure than a 128 bit (public) RSA key (which can be considered almost trivial to crack).

cheers for remarkably quick reply there Tangent. So basically when talking about hardware the number of bits governs how much it can do at any given point in time, and when used in relation to software, it concerns the length or number of 'things' - more being better and more secure/reliable. Have I pretty much got the gist?

edit: apologies for the unscientific use of word 'things' above!

Just to expand very slightly on what Tangent said, 1 byte = 8 binary digits (bits). A processor described as a 32 bit processor moves data around using 32 bits as the basic unit of transfer. A 64 bit processor moves data around 64 bits at a time, etc. In simple terms, the larger the unit of transfer, the faster a processor will appear at a given speed. However, in order to take full advantage of the processor, the Operating System also needs to be able to work in the same way.