Differences between British and American English Conversations

In this video, Alisha answers 5 questions. - What's the difference between "not related to" and "nothing to do with"? - Hey Alisha. I ran across the word 'overlap,' with a meaning like 'meet'. For instance: 'we never overlapped.' Does that mean "we never met before" or maybe "we never met accidentally." Is this correct? Or close? - What is the difference between 'As and While'? For example, While I was walking, I ate an apple. and As I was walking, I ate an apple. When do i use "as" and "while"? - Hi Alisha. What's the difference between till and until and how do we use them correctly? - What's the difference between American English conversation and British English conversation?