The difference between "behaviour" and "behavior" is simply one of spelling, dictated by regional variations in English.
British vs. American English
The distinction lies in whether you are using British English or American English:
- Behavior: This is the standard spelling in American English.
- Behaviour: This is the standard spelling in British English.
Summary
In essence, both spellings refer to the same concept – the way in which someone conducts themselves or acts, especially towards others. The choice of spelling depends entirely on the context and which regional dialect of English is being used.