Yes, it does exist, but Joe has not given you the full story: it is NOT a simple question of American/British spelling like color/colour.
Here are the facts:
In British English, there IS a difference between 'practice' and 'practise'. They are different words. The word 'practice' is a noun - as in "I need some practice" or "This practice is dangerous" - while the word "practise" is a verb - as in "I need to practise" or "I'm practising my dance steps".
In American English, both the noun and the verb are written the same way: always with a 'c'.
Word of advice: Always wait a while until someone comes along with the correct answer rather than clicking 'Best Answer' straight away. The first answer you get isn't necessarily the right one !