What's the difference between MyISAM and InnoDB?

I understand that this question has been asked before, but most of the time it is asked in relation to a specific database or table. I cannot find an answer on this site that describes the two engines and their differences without respect to someones specific database. I want to be able to make more informed decisions in the future with respect to designing a table or database, so am looking for a comprehensive answer on the differences between the two storage engines. What's the difference between [MyISAM][1] and [InnoDB][2], and what should I be looking for when trying to decide between one or the other? [1]: http://en.wikipedia.org/wiki/MyISAM [2]: http://en.wikipedia.org/wiki/InnoDB