What is the 3 oz rule for flying and how does it impact carry-on luggage restrictions?

The 3 oz rule for flying refers to the Transportation Security Administration (TSA) regulation that liquids in carry-on luggage must be in containers of 3.4 ounces (100 milliliters) or less. These containers must be placed in a clear, quart-sized plastic bag. This rule impacts carry-on luggage restrictions by limiting the amount of liquids that passengers can bring on board to ensure safety and security during air travel.