Before "clarifying" something, make sure you understand it. "Shorting" is not a financial instrument. It simply means selling shares that you do not own. A financial instrument is something one can trade.
Options are a financial instrument because once you buy the right to buy or sell a share at a specific price (i.e an option) you can trade that right depending on how the share price fluctuates.
I'm not sure which operation is more "dangerous" (short selling a stock or buying put options). Options provide a bigger leverage but have no value past the strike time; the loss is however limited to whatever premium was paid to buy the option is one chooses not to exercise it. The risk in short selling is that you may end up having to buy the stock at a price that is much higher than you anticipated, so the worst case scenario is that you may have to keep that stock for a long time hoping that the price will go up again, or sell at a loss. In either case you need to have a good bankroll because most trading companies will require additional funds (or credit) to secure the position when the price of the underlying asset fluctuates wildly in a direction that does not favor you (otherwise they will liquidate).