Hinayana is known as the lesser vehicle.
Mahayana is known as the great vehicle.
I would say that one of the most important details that create a distinction between these two types of Buddhism is that those who travel the Hinayana path are concerned with personal enlightenment in this current lifetime. The concern of Mahayana Buddhists is to help all beings become free of suffering and attain enlightenment.
Neither school can exist without the other. How would you know you were practicing one philosophy without the presence of other philosophies to identify and differentiate? This is the definition of emptiness: that all things are interdependent, and none can exist without each other. Therefore, there is no 'other".
We are all dependent on one another and we all walk the path.