What is the difference between Intelligence , Knowledge , Genius ?

Knowledge is simply things that one has learned, through learning or experience.

'I learnt a lot at school but I can't put any of it to good use.'

Intelligence is the ability to use what knowledge you have, in a constructive or efficient way.

'I didn't learn a lot at school but I was able to adapt and use what I knew, to my advantage.'

Genius is a subjective assessment of someone's knowledge or expertise.

'It doesn't take a genius to know that knowing a lot doesn't make one a genius, only knowledgeable.'

The definition of intelligence is controversial. Groups of scientists have stated the following:

from "Mainstream Science on Intelligence" (1994), an editorial statement by fifty-two researchers:

A very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—"catching on," "making sense" of things, or "figuring out" what to do.

from "Intelligence: Knowns and Unknowns" (1995), a report published by the Board of Scientific Affairs of the American Psychological Association:

Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person's intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of "intelligence" are attempts to clarify and organize this complex set of phenomena. Although considerable clarity has been achieved in some areas, no such conceptualization has yet answered all the important questions, and none commands universal assent. Indeed, when two dozen prominent theorists were recently asked to define intelligence, they gave two dozen, somewhat different, definitions.

http://en.wikipedia.org/wiki/Intelligence

Knowledge is a familiarity with someone or something, which can include facts, information, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject. It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); and it can be more or less formal or systematic.

http://en.wikipedia.org/wiki/Knowledge

A genius is someone embodying exceptional intellectual ability, creativity, or originality, typically to a degree that is associated with the achievement of unprecedented insight.

There is no scientifically precise definition of genius, and indeed the question of whether the notion itself has any real meaning has long been a subject of debate.

http://en.wikipedia.org/wiki/Genius

Intelligence is a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience.

Knowledge is a familiarity with someone or something, which can include facts, information, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject.

A genius is someone embodying exceptional intellectual ability, creativity, or originality, typically to a degree that is associated with the achievement of unprecedented insight.

Knowledge is a true reasoned belief.

Intelligence is the capacity for knowledge. One is typically referred to as having high intelligence if one is capable of reasoning particularly well and thus being better able to form true reasoned beliefs. Other times, one may be referred to as having high intelligence if one has a good memory and is therefore capable of holding many true reasoned beliefs at once.

Genius is the quality of having a high intelligence.

Intelligence is knowing one is not a genius,,