People, businesses, and the government have disputes.
Courts are institutions created by a government to settle disputes through a legal process.

Georgia Farmer sold Florida Grocer $100,000 worth of peaches.
Florida Grocer failed to pay for the peaches, saying they were spoiled.
The court will decide if the peaches were spoiled or whether Florida Grocer owes Georgia Farmer for the delivery.
The government accuses someone of a crime. Courts decide whether the person committed the crime, and, if so, what the punishment should be.
Did Frank Clark rob the bank, or was it someone else?
If it was Frank Clark, how should he be punished?
Court decisions affect other people, in addition to the parties involved in the lawsuit.