Anon,
All provinces pay federal taxes. Equalization is the amount a province receives back from the government. Some provinces receive more money back from the federal government than they have put in. Other provinces receives less money back than they put in and in some cases the maountnis much, much less.
In the case of Alberta, out of the billions it has contributed to the federal coffers, over the lifetime of the equalization payment program it has received a mere $92 million back from the federal government. Alberta has contributed something in the range of $600 billion!!!
So, per capital, Alberta has contributed far more than any other province and despite our current dismal economic state we still do.
More populous provinces such as Quebec and Ontario contribute more overall dollars, but per capital contributions are far less. Quebec has always received more than it has put in to the federal coffers.
When you look at the overall map, with the exception of Manitoba (MB), the west has been supporting the east for a very long time.
So you answer your question, the equalization system is a very unfair system where the wealth from the west is being redistributed to the east.