If taken completely literally: "I want..." describes a desire. Ex. I want to go to Europe next year. "I would..." describes a hypothetical situation. Ex. "I would like to go to Europe next year." If you're asking for something, saying " I want..." is very rude. This makes sense when you think about it: just saying that you want something when you're obviously asking for it implies that the listener must do something just because you want them to, as if they were a slave or servant. "I would like..." is much politer. By simply stating that you'd enjoy a hypothetical something if you had it, you're not directly asking for anything. I guess it could be imply the same thing as "I want...", but it's never interpreted that way. "I would like..." is really short for "I would like to have..." (when you're asking for something), but people usually omit "to have".

I want can sound rude in some contexts and I generally avoid the use of I want. I would like is a polite form of I want :)

"I would like to order the pork chops please" is more polite than saying "I want pork chops". The meaning is the same, It's a potential tense.

That is what I want <---- more aggressive , invading , I suppose

Jmat, Kleo Ng, Daniel! Thank you very much for your help! Very clear ))