What do you mean by system of the ‘Checks and balances’ in a democracy?

In democratic countries power is shared among different organs of the govt. such as legislature executive and judiciary.
i. These organs are placed at the same level to exercise different powers.
ii. None of the organs can exercise unlimited power. Each organ check the others. This results in a balance of power among various institutions for example. Even though ministers exercise power they are responsible to the parliament or state assemblies similarly.
iii. Judges are appointed by the executive they can check the functioning of executiveand legislature. This arrangement is called system of checks and balances.