In the federal government working, the motive of checks and balance system is to control or limit the power of one branch of government from using more or becoming too powerful. In simple words, this system make sure that one branch of government cannot use its power than mentioned (keep a balance between the difference branches of the government).
This system ensures that all the branches of the government use the limited powers as mentioned in the constitution and not more than that. This system is an important section of the constitution.