What is the difference between French immersion and core French?

I imagine you are talking about different forms of teaching language. Core French would be when the language is taught through exercises in basic grammar and structures (ie a more fomal style of teaching), whereas the term 'immersion French' is used when the student is put into a learning situation where only the taget language is spoken - the idea being that he or she will pick up the language in a more natural way.

Core French is when a student has only one classes where they learn French, that being French class. French Immersion is when all of a student's classes are in French (ex. Science, Math, Social Studies, French). The French class is more advanced in French immersion. By the time a student has finished high school in French Immersion, he or she should be considered bilingual, whereas students who only take core French have only the basics of the language. The only classes not in French while taking French immersion are: English, P.E., Music, Art...