At first glance, it can be hard to tell what those funny numbers on the bottom of the container can mean. A lot of food is wasted simply because people don't take the time to look closer and try to understand it before they just toss it in the trash can. Below are some helpful reminders I've made based off of my research, to help guide you the next time you're out shopping or cleaning out the ol' fridge.
BEST BY indicates when your food will still be at peak freshness. It will likely still taste good even if your food is a bit past the printed date, so use your best judgement to determine whether you should keep it or toss it. For example, if your mozzarella is more orange than white and has spots of mold on it, you should probably avoid eating it.
SELL BY is largely intended to be used by retailers, who remove products past this date from shelves to make room for newer products. However, the food itself is almost always good for at least a week after the date printed.
USE BY indicates when an item might start to go bad. This is largely about quality rather than health and safety, so once again use your judgement to determine if an item is still safe to eat. Food past the "use by' date might be a bit stale, but it's by no means guaranteed inedible yet.
EXPIRES BY indicates that food will likely be unsafe to eat past the printed date. This is the ultimate sign that your food should not be consumed past the date on the container, and can often be found on perishable goods like meat and some produce.