Could someone explain the concept of judicial review and its impact on the balance of power in the United States Government?

Question

Judical review means that the courts can review congressional and administrative actions to see if they are constitutional.

The Supreme Court gave itself he power of judicial review in the case of Marbury vs. Madison in 1803.

The Supreme Court in later times became in effect a coequal branch of government with Congress and the President. Without judicial review the court could not inducate that an action or law went against the constitution. Previoulsy the check in our system were aligned against the judiciary. Now the Supreme Court could check the other two branches.