Please would somebody tell me what overclocking is ? (in detail)
/////Overclocking is running your computer faster than it was factory spec'd to run, by manipulating default voltages and speeds of hardware components.
What do you need to overclock ?
/////Overclockable hardware and the education of How to do it.
What does overclocking depends on ? (like RAM, CPU, GPU etc.)
/////Hardware capabilities and the extent of your overclocking knowledge.
What can BE overclocked ? (RAM, CPU, GPU etc.)
/////All of the above
Can any computer can be overclocked ?
/////No
What are the advantages and disadvantages of overclocking ? (temporary/permanent and long-term/short-term)
/////Advantages, really all boil down to getting more than you actually paid for.
Disadvantages, are the bad electrical burnt smell from a serious overclock failure, is hard to get out of the room and nose hairs.
Since you're entertaining the thought of overclocking then thoroughly educate yourself first, read the overclocking guides, search the internet for different overclocking websites, get a real solid background under your belt.
Learn First, Then Do!
Then you'll have more specific questions targeting an exact obstacle you need to overcome, to achieve the overclock you may be after.
But we all have to start somewhere so good luck!