How are call options different from put options and when to use them in markets?

What are the different ways in which I can use options for trading in the markets?

Are options really useful in playing uncertain markets?

Are there any specific risks in selling options; either calls or puts?

How are futures different in concept from options?

Let us say that the markets are extremely range bound; can I still use the options to make some profits in the market?

What are the driving factors for deciding between buying a put option and selling a call options?

What are the practical uses of index options and who are the users typically?

What can we interpret realistically from the accumulation of out of the money calls and put options?

I am planning to sell some call and put options. Are there any risks in it?

I am planning to start options trader more as a buyer of calls and puts. Are there some basic things that I must remember?