The Right, not the Obligation

Buying gives you the Right

• Buying an option (call or put) conveys the right, not the obligation to buy (call) or sell (put) an underlying instrument (eg a share).
• When you buy an option you are NOT obligated to buy or sell the underlying instrument - you simply have the right to do so at the fixed (exercise or strike) price.
• Your risk, when you buy an option, is simply the price you paid for it.

Selling (naked) imposes the obligation

• Selling an option (call or put) obliges you to buy (put) from or deliver (call) to the option buyer.
• Selling options naked (ie when you have not bought a position in the underlying instrument or an option to hedge against it) will give you an unlimited risk profile.
• Combined with the fact that you are obliged to do something, this is generally not a preferable position to put yourself in.

Now let's consider the words "to buy or sell an asset":