The government apparently wants us to save for retirement (not always obvious because it also wants us to spend as much as possible to pump the economy going into the next election cycle). To encourage this, it has created some ways to save that avoid or defer taxes: IRAs and 401ks.
It is a bit of a downer to think about, but we are all going to die. Do we care what happens to our loved ones (if they really are "loved" than the answer is obvious). This tutorial walks us through the options to insure our families against losing us. The reason why we stuck it in the "investment vehicles" topic is because it can also be an investment that we can use before we die.
Hedge funds have absolutely nothing to do with shrubbery. Their name comes from the fact that early hedge funds (and some current ones) tried to "hedge" their exposure to the market (so they could, in theory, do well in an "up" or "down" market as long as they were good at picking the good companies). Today, hedge funds represent a huge class investment funds.
They are far less regulated than, say, mutual funds. In exchange for this, they aren't allowed to market or take investments from "unsophisticated" investors. Some use their flexibility to mitigate risk, other use it to amplify it.