If it can be briefly explained in one not too long sentence then sure, why not.
Maybe just saying that "codecs are codes which allow certain audio or video formats to play". It could probably be said better though.
I've linked to word 'codecs' to the wikipedia page on codecs - is this okay? or should we use a less editable link?
hmm, on second thoughts would this be better:
===Freedom with Digital Formats===
This is a big part of Freedom when it comes to computers. Say you download a file, it's a Windows Media Video - what do you do if you don't have Windows Media Player (WMP)? There's no free software you can use to view it (without proprietary codecs*). You have to go out and buy WMP, even if you get WMP and open it, how do you know what the file truly is?
Now, go and download an Ogg Theora video file. There is plenty of free software out there you can use to view it. You can even look inside with the right Free tools to make sure you know what's exactly in that file.
But why the difference?
Well Windows Media Video is a proprietary format which is closed to the world, you have no idea of how it's encoded or decoded because its specification is kept secret. On the other hand Ogg Theora is a free format, which is nice and open to the world, the specifications are freely available to read and use; this is the reason you can get free programs that run the format.
* Codecs - These are bits of code wich allow you to play audio and video formats.
I wouldn't oppose either of the methods but it seems like the second one would be better. You could do both though, link codecs to wikipedia entry and leave a note at the bottom about codecs. As long as the reader can easily see what it's about it should be ok. Links to some extra information shouldn't hurt either.