What money really is?

Before Beginning to understand the world of finance first let's grasp the idea of its foundational bricks. 

Human is a Social Animal. From its very origin we humans have understood that a lone wolf dies but pack survives.Thus Humans have inculcated the very idea and have survived to become the greatest species on the planet.Now among humans we needed something to deal with each other. So that one person's expertise can be benefited by some other person in exchange for something and vice-versa. Earlier it was done in the form of barter system where goods were exchanged. Like a person has plenty of rice and is in need of wheat, he could exchange the rice for wheat with a person who had plenty of wheat and was in need of rice. This was a barter. But what if the other person who has wheat doesn't want rice in exchange. A problem will arise of demand & supply.

Thus Money was introduced as an instrument, which was generally acceptable in exchange of all goods. It made the transactions easier. Hence MONEY IS AN INSTRUMENT FOR EXCHANGE.
Do not confuse money with wealth. Money is liquid asset which doesn't increase its value rather its value decreases with more supply of it.