"Bäst före" can be translated to "best before" (Best By). In Sweden this is a mandatory marking for food and beverages. It means that the producer guarantees that the product will taste and look as intended until this date. Usually nothing happens after this date and consumption is not harmful. Eventually, however, the quality of the product will decrease. After the best before date, spices can taste less, yest may not work as good and things like that. Food that is stored right can stay fresh long after the printed best before date.
The National Food Administration of Sweden can explain more about this marking.
Smell, look and taste. Don't just throw away food. Your senses are often perfectly suitable to judge if the food is eatable or not.
Use by date (Expiry date)
"Sista förbrukningsdag" or use by date is something completely different than the best before date, don't mix them up. Food that have passed the expiry date should not be consumed.
Manufactured date (MFG)
Some items are marked with the date that they were manufactured. This is obviously always a date in the past.