Good code vs bad code

Good code is generally well commented and documented although that's probably said too often so I'll keep going.

Good code means avoiding replicating code more than once this probably applies to scripting/programming languages more than HTML and CSS. But, if your doing the same thing twice or more then it's time to take that code and make it a function. If you have long functions where code is duplicated it is probably a good idea to break that function down into separate functions as well.

As said in some of the treehouse videos you want "DRY" code. Don't Repeat Yourself.

To expand on what Joshua said, more so than even well documented is code that is easy to read and flows well. This would be very hard to describe, it's something you start to gain with experience. Some code is just a pain to look at and try to follow it, some is quite easy to look at and follow what's going on and happening. The latter would be considered good code. One thing I think helps with this would be good variable and function names, good alignment of the code, no overly complex method in method in method to get info, at least not complicated ones that wouldn't make sense to another viewer.