In what significant ways are Jim and Huck alike and different?

I think the following points of comparison
are significant:

• Both are very
  superstitious - which connects them in some ways, provides conflict
  at other times.


• Both are running
  away and hiding in the process - this is the foundation for the entire
  novel.  The reason they need and rely on one another is due to this
  commonality.


• Knowledge and
  education - while Huck has attempted formal schooling and Jim
  hasn't - both have a very mixed up view of the things they discuss on the river.  Both
  have obtained most of their knowledge from experience - rather than books (or someone
  else teaching them), which makes for some humorous stories, gullibility, but also a keen
  sense of right and wrong based on intuition.


• Both, at the
  core of themselves, are kind hearted and mostly honest
  (with the important things), and this makes them genuine in their friendship
  with each other.

The significant differences
are a little more obvious:

• Their ages
  - this provides a lot of opportunities for situational irony because Huck is
  just a child and Jim is a full grown man, but at times, the role reversal between the
  two is laughable.


• The fact that Jim is a black
  slave and Huck is white and free (and subsequently
  wealthy though not by birth) - seems like it should create a big opportunity for
  conflict.  Again, ironically, the two not only get along - but manage to even disagree
  civilly when it comes to racial matters.  This is one obvious difference between them on
  the outside that doesn't affect them as much as it does others, on the outside.