Purpose- used as intended. Some people say, I want to achieve my purpose, but this is not the only way to use this word and it also means the person wants their life to be completed as intended possibly by a higher being like God. Aim- often a short-term goal. More spontaneous than a formal goal, that may not have a specific plan. Goal- something you want to accomplish in a defined way- the outcome.

A very good question. This is a great question, and a very tough one. Because you can use these words interchangeably, and most people do. Technically, both words mean the same thing: "I have a goal" = "I have an aim" However, the nuance is slightly different. I feel (this is just a personal opinion), that 'aim' is a general and broad 'thing' you are going to achieve. If you are to compare the two words together. "I aim to be fluent in Spanish" "I aim to please" "I aim to travel the world" "I aim to misbehave" How you intend to be 'fluent in Spanish" = maybe you listen to a Spanish podcast for 10 minutes a day. This is your goal. "My goal is to listen to a Spanish podcast for 10 minutes a day". A goal is more specific and something you will do, in order to achieve your aim. I also think an 'aim' is less definite, you 'aim to do something', but that doesn't mean you are able to 'do' what you aim for. Whereas a 'goal' doesn't have that nuance. Its a tough question, and I think, in context, if you say aim or goal, people will understand what you mean, and I don't think you would need to define the difference. I hope this helps, I think I confused myself ;)