What happened to biscuits not stored in airtight container?

When biscuits are not stored in an airtight container, they become stale and lose their freshness. This is because the air contains moisture, which can cause the biscuits to soften and become chewy. Additionally, the air can also cause the biscuits to oxidise, which can lead to a loss of flavour and nutrients. To prevent this, biscuits should be stored in an airtight container in a cool, dry place.