British English or American English?

Both are acceptable, but….

There are differences in spelling, vocabulary and grammar. But first consider your audience; if you are communicating with a British, Australian, Indian, South African or New Zealand audience, it’s preferable to use the British conventions. If communcating with Americans or Canadians, then use American English.

Spelling—there are many (but minor) differences; British will use 'harbour’ and Americans, ‘harbor’. Others are defence/defense, enrol/enroll, analogue/analog, colour/color, tyre/tire and metre/meter.

Vocabulary differences tomorrow.