What's the difference between these two words?

I was wondering if there is a difference between "practice" and "practise", or do they mean the same thing, but just with different spellings?

Well it kind of depends on where you are.
They are effectively the same thing however:
In most parts of the English speaking world (UK, Ireland, Australia, Canada, and South Africa) 'Practice' is the noun and 'Practise' is the verb.
Eg:
-Dr Smith has to attend his practice.
-John is going to practise his German.

However in America the spelling 'Practice' is often used for both the noun and verb. A small minority use the 'Practise' spelling for the verb and the other for the noun.

Yup, "practise" is used chiefly in the UK.

go to dictionary.com

practice is a noun.
practise is a verb.

how about we form an international movement to clear national spelling differences up?

as long as it doesnt involve mnovement. im too lazy

I'm from USA---we use practice for both its verb and noun forms. we do not use "practise". we recognize that as spelling used by other countries for the same word.