Okeydoke. Just how do you expect to get anything with detail into 833 bytes...
Compression is just like squeezing a sponge, and then letting it go. Everyone with a computer uses compression in one form or another, from Zip files and Stuffit archives to the way your modem talks to the internet. As an added bonus, it's a lot easier than it seems.
Consider the (now classic) sentence 'the fat cat sat on the mat'. A compression algorithm will scan this and notice that there are more than a few instances of the phrase 'at ' and a couple of 'the'. So it says to itself 'let's make the letters 'at ' be @ and 'the ' will become &' So our sentence now reads '&f@c@s@on &m@' (Think about it...) which means our letter count has gone down from 26 letters to 13. Admittedly we do not get 50% compression because we need to tell the archive what the @ and & mean, but it is still not too bad.
If this is applied to a larger file the results are quite revelatory. Images get more interesting. Let's say we have an image 100x100 pixels at 8bit colour depth, and we
Hang on, what's colour depth?
First off, it's the correct spelling of colour, but that's getting pernickety. Colour depth is the level of information stored in each pixel (or dot). 8 bit refers to 8 binary digits (ones or zeros to the the not techies) which count in base two. All you need to know is that 8 bit will give you 256 colours, 16 bit gives you 65536 and 24 bit is just over 16 million (coincidently the maximum number of colours the human eye can discern. If you want to go to 32 bit colour you might want to refer to Big Lie One for inspiration). 8 bits is one byte (four bits is a nybble, and 16 bits is a word, fact fans) so each pixel costs one byte, as it were.
So, our 100x100 pixel image has 10,000 pixels, and is 10Kb uncompressed. At 16 bits it would be 20KB, and at 24 bit would be 30KB. Sticking with 8 bit for now, imagine that image is a large black square. Here's one I made earlier:
This image should be 10240 bytes, but instead it is 162 bytes. That's because the compression looked at it and thought, that's just a load of black and the final file says something along the lines of 'one hundred lines of one hundred black dots, and a creme egg please'.