Federalism is a system of government in which sovereignty is constitutionally divided between a central government and constituent political units like states.
The most important thing to know is that it is illegal, and you cannot have a platypus as a pet.
It is not particularly important to know the principle: knowing how and when to apply it is good enough. A postgrad degree in maths and 30 years in the profession and I did not even know what it meant until I saw this question and did a bit of research!It is important because it enables you to rescale (rename) fractions which allows you to perform addition and subtraction.
he is smart
so we can know thing better
it is important to learn legend so that we can know how a thing is made
So that we know about geography and we can get a good job and all that sort of thing. and do the right thing.
You can learn important information by buying the The Schwarzbein Principle book and know more about food and diet. As well, How stuff works provides an interesting article to this subject.
by leaning the things that are more important on your job
The Heisenberg uncertainty principle is that the more you know about the speed of a particle the less you know about it's speed, and vice versa. This is because the more specifically you know where a particle is, the larger area there is in which there is a reasonable chance of finding a particle in within a time boundary, due to the interference effect. The reason the more you know about speed the less you know about position is a little more complicated. It is important for a number of reasons. For a start, there is another expression of the theory allows you to know bits and bobs about the particle. The other thing is that it is revealing about the nature of the way particles spread out, and is important in some equations and calculations
The most important thing any living person knows or pretends not to know " IS THE EXISTENCE OF THE UNKNOWN, OMNIPRESENT" The most important thing ever is acutally staying healthy and drinking lots of fresh water.
Federalism or Checks and Balances I dont know.
Google it. It will tell you everything you need to know.