Re: What exactly is bird flu?

yes, it is. You can find A LOT of info on google .
The virus strain is called H5N1 and is of the greatest concern because of its high mortality rate . Although it has already been trasmissed from birds/pigs to humans, it seems that at the moment human-to-human transmission is not possible ( there have been several claims of in Asia, but WHO never confirmed them. no one knows for sure). This virus can mutate and spread very easily and its behavior is very similar to the Spanish flu virus of 1918. There are no vaccines/drugs that seem to work at the moment. Deaths by H5N1 mainly occur because of a respiratory distress syndrome which results from overstimulation of Immune System (cytokine storm, a sort of self-intoxication) , so having a good immune system is not enough to protect us.
Go look for basic info on WHO site ( FAQ ) , then I suggest you to go further, there's a lot of info on the web .