What are the two most important aspects of capitalism?

The two most important aspects of capitalism would first be the private ownership of the means of production. That is, land, factories, etc. are not owned by everyone but are owned by a few, the capitalists. The workers must try to sell their labour power to the capitalists in order to survive. Secondly, the driving force of capitalism is the accumulation of capital for the sake of the further accumulation of capital. It must grow and expand at whatever cost, otherwise a crisis will promptly follow.