The Internet's discourse is dominated by American English, so you may have noticed that I spell certain words unconventionally. This is because I am Canadian and use Canadian spelling. To clarify and help you to recognize the differences, here is a list of common words that have different spellings between American and Canadian English.
To people who don't speak English natively, this may be confusing - and it is even more confusing to know that each Anglophone country has its own conventions (Australia, Ireland, Canada, the USA, South Africa, India, the UK, New Zealand, Singapore, etc.). Thus, I encourage you to learn the spelling conventions of your local Anglophone culture and adapt accordingly.