Overwrite vs. Override

What's the difference between these two words?
I've seen them used somewhat interchangeably and have wondered if it's on purpose or because they sound alike. So, here's the definitions.

OVERWRITE
From the American Heritage Dictionary
http://dictionary.reference.com/browse/overwrite
.o·ver·write
v. o·ver·wrote , o·ver·writ·ten , o·ver·writ·ing, o·ver·writes

v. tr.

1. To cover (something) with writing.
2. To write about in an artificial or an excessively elaborate, wordy style.
3. Computer Science
a. To destroy or lose (old data) by recording new data over it: accidentally overwrote an important document.
b. To record (new data) on top of already stored data, thus destroying the old data: overwrote an updated document on top of an earlier draft.


v. intr.
To write artificial, excessively elaborate, or wordy prose.


OVERRIDE
From the American Heritage Dictionary
http://dictionary.reference.com/browse/override

o·ver·ride
tr.v. o·ver·rode (-rōd'), o·ver·rid·den (-rĭd'n), o·ver·rid·ing, o·ver·rides

1a. To ride across.
1b. To ride beyond.
1c. To prevail over; conquer: Budgetary concerns overrode all other considerations.
1d. To declare null and void; set aside: overrode the President's veto.
1e. To counteract the normal operation of (an automatic control).

2. To trample on.
3. To ride (a horse) too hard.
4a. To prevail over; conquer: Budgetary concerns overrode all other considerations.
4b. To declare null and void; set aside: overrode the President's veto.
4c. To counteract the normal operation of (an automatic control).
5. To extend over; overlap.



I think people have been writing "override" when they mean "overwrite" and this is especially true with "over ridden" and "over written." Of course, people in the computer industry are the worst culprits.

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