If you are looking for the dictionary definition of an intersection I can give you that. This is it...
                                The word intersection is a noun, it has three definitions. #1. The act or process of intersecting. #2.  A place or area where two or more things ( as in streets) intersect. #3. The set of eliments common two or more sets; especially: the set of points common to two geometric configurations.
    If you still don't know what an intersection is , if you have ever been to Los Angeles there are about fifty million of them (exaggeration), probably only about 30.