Example 1: If your sink is leaking water, a plumber will come to fix it so no more water spills on the floor.
Example 2: When a new bathroom is built, a plumber puts in the pipes and makes sure everything works well.
Example 3: If the toilet won't flush, a plumber can see what's wrong and fix it so it works again.
Fun Fact: Plumbers often use tools like wrenches and pipes to do their job, and they help keep our water safe and clean!