Bitcoin (BTC) is a digital store of value. It can be traded with traditional currencies such as the US Dollar (USD). Bitcoin can be digitally transferred between people globally. It is also decentralised– without any governing or controlling body. It cannot be frozen by banks, or confiscated by governments.
Bitcoin’s special feature of decentralisation stems from the fact that central authorities are a point of weakness as they have so much power they can be used against its users’ interests.
For example, banks commonly lend peoples’ deposits to other banks etc. However there have been cases where banks have failed to repay their creditors and collapsed. While some governments do offer deposit protections, the amount protected is limited.
Bitcoin solves this problem because with decentralisation no one, including the banks or the government can take your bitcoin i.e. your digital wealth.