Bitcoin is a lot of things:
1) It is an amazing piece of technology. The open source software manages a shared database which is just in big 'transaction log'. 'Mining' is validating the transactions on the bitcoin payment network. Bitcoin software is distributed. No one entity controls bitcoin. Most mining is not in China.
2) Bitcoin is a payment network that has almost no fees when compared to credit card and transactions are validated almost immediately and cannot be rolled back. (An ebay type site without CC/PayPal fees and instant payment is possible with bitcoin. You can do escrow too.)
3) bitcoin is like cash in that you store it and transfer it as you please. No need for any counterparty risk. Bitcoin is NOT like cash as in that no central authority can create it out of thin air. (which what is happening to all global fiat currency right now. You cannot 'Quantitavily Ease' bitcoin like the Federal Reserve is doing to the USD)
4) bitcoin is like gold in that there is a limited amount of bitcoin and they are mined at a known rate. Bitcoin's value cannot be inflated away. Bitcoin is easily divisible. (You can have .00000001 bitcoins) Bitcoin is NOT like gold which is difficult to store and it is easily divisible.
5) bitcoin could make central banks obsolete
It takes a bit to get your head around bitcoin, but if you understand what money really is (fiat currency), how money is controlled today (fractional reserve lending), and some technology, bitcoin is beautiful.
Here are some good resources.
https://en.bitcoin.it/wiki/Main_Page
http://reddit.com/r/bitcoin
http://evoorhees.blogspot.com/
Bitcoin will likely fail, but the concept and and the fairness and honestly in money/transactions it could bring are hopefully here to stay.
PS....I know I drank the koolaid a bit. Cannot recommend putting significant money into it. Very high risk.