Another good analogy here is definition of life. What is life and what is a difference between a living being and a glass of water? The difference is that they are different systems that work in different ways, for a system to be conscious, it should work in a certain way, and a glass of water doesn't work in that way, that's why it's not conscious. Consciousness should perceive reality, remember, model and analyze it, maybe even have intelligence, will, abstract thought, attention and reflection, then it can be seen as consciousness.