Behaviour

Familiar you could be  walking on the street and see someone that you think you have seen

 before and that is being familiar

Or if you saw a pic on face book and you think you know them that is being familiar or if you see someone at school and you think that you have seen them at another school that is being familiar

 Introduced introduced means you're showing someone to someone or someone is introducing you to someone that menes thay are showing you to someone that you dont know 

Or you are introducing a pet to another pet

Behaviour means are you being good or bad or i could say you have bad behaviour that means you are naughty all your behaviour is good if your behaviour is good you are not being naughty but if you were behaviour is bad you are being a naughty boy