Hedge Fund in a Nutshell

What is a hedge fund? According to Wikipedia: "A hedge fund is a private investment fund which may invest in a diverse range of assets and may employ a variety of investment strategies to maintain a hedged portfolio intended to protect the fund's investors from downturns in the market while maximizing returns on market upswings." Notice here, "diverse range of assets" and "variety of investment strategies" to maintain a hedged portfolio. What are those diverse assets? Namely, equities,commodities,and bonds. What about "variety of investment strategies"? Well, it involved with using options to take both long and short positions. Actually, I heard there are hundreds of strategies in hedge fund industry. The long/short strategy is the basic one and it's in accordance with the name "hedge". In order to uilitize those strategy, you need to know about "options" and how it works.