Overwrite or override

The common used word is Override and it's not language-specific as you can also read from wikipedia: http://en.wikipedia.org/wiki/Method_overriding

Both are generic terminologies Override is the prevention of some previous action or decision and on the other hand Overwrite refers to something being written over something previously written.

in simple words,

Actions and decisions are overriden.

Information is overwritten.

If you're replacing one implementation completely with another, it's "overwriting" or more commonly "replacing". If you're replacing an implementation with another for some specific cases, it's "overriding".

To "overwrite" something is to put something else in its place, destroying the thing overwritten. To "override" something is to cause something else to operate instead of it without harming or changing the thing overridden.