Wrapping food to keep bacteria away

The way the food is packed in to mean a lot for how long it can keep and how much bacteria can grow.
Wrapping can help protect against bacteria from the outside. And wrapping can be so dense that there can't get air and water into food. It gets food to last longer, because most bacteria need water and air to grow.
You can for example get someone in a can that is so close that there can be air or water into another method is to pack the food quite close in and afterwards sucking all the air out of the wrapping. It's called vacuum packed foods.

The food is usually more durable when it is wrapped up and has not been opened. Even if it is not canned or vacuum packed. Everything from milk to bread, chocolate deli meats, rice and oatmeal stays longer in its packaging when it is not opened.