Words ending in "-ize"?

[irmamar]

Sometimes I've read words ending in "-ize", such as "realize", written with "s" instead of "z" (realise). Is it correct? Tanks.

[Tomisimo]

They are spelled "-ize" in North American English (US/Canada etc) and they are spelled "-ise" or "-ize" (both are acceptible) in British English (UK/Australia etc.)

[irmamar]

I'm a student of British English, but I thought it was on the contrary, that "-ise" was typical of American English. Well, I've just arrived and I'm already learning something. Good!