Checks and balances is the idea behind limiting the power of government branches (legislative, executive, judicial) by giving each branch the ability to "check" and counterbalance the power of the others. For example, the president can veto a law passed by Congress, but Congress can override the veto if they have enough votes. Checks and balances also are known as separation of powers, as they typically ensure that political power is not concentrated in the hands of a single authority.
The preamble is known as the introduction to the constitution, used to show the constitution's powers regarding benefits of liberty. It was written by the founding fathers of the United States, and it states that we have the ability to speak our minds, we are treated fairly and equally, and that the state has no authority to take that away from the people.
It is improbable that our amendment will be changed or altered in the near future. After all, it is still a valuable piece of American history--the original documentation from our founding fathers. These amendments were what gave us the rights we have to our daily life's today.
