What is the FIFO method (first-in, first-out)?

Because all food becomes less safe over time, it makes sense to use the oldest food first and save the newest foods for later. Not only does this promote food safety but it also contributes to the overall quality of food in the establishment. It also reduces waste by preventing food from being discarded when it could have been avoided. Although the FIFO method is effective, it should not replace other rules regarding time and temperature.