It isn't easy to describe what bitcoin is all about in simple terms. One of the core features of Bitcoin is decentralization. Instead of trusting a centralized authority, Bitcoin allows people to transfer value on a peer-to-peer basis. This is a radical change from the established system, but it is only a part of what went into the design philosophy of Bitcoin.
Since the beginning of recorded history, there has been a centralized authority that decides the most important things for the society. The entity that was at the center of the system has changed, and today the central banks and money center banks work with the governments to maintain a position of power.
Bitcoin was the first system to demonstrate that advanced technology can do away with the need for a centralized authority. People can organize themselves in whatever way they wish, as platforms can be created along any lines that the users desire.
In a way, Bitcoin is about connecting people in new ways, and limiting the role that centralized authorities have globally. These changes could extend to governments, the financial system, shipping systems, and any other system that uses authority to concentrate a position of power.
The move towards decentralization is just beginning, but what Bitcoin did to ignite this movement can't be overstated.