What is the definition of checks and balances? i'm doing homework and i need a simple definition for 'checks and balances'.

Checks and balance is a system that used to limit the power of Government branches.

In order to limit their power, most government usually divided into three branches :
- Legislative branch, whose duty is to create the law
- Executive branch, whose duty is to impose and execute the law
- Judiciary branch, whose duty is to interpret and judge the law

Clean air provides nitrogen

My opinion is that it doesn't