Food preservation in cold temperatures has been practiced since the early days of mankind, although not as effortlessly as today.
We have powerful freezers, polythene bags and plastic containers, freezer labels and other utensils that help us better preserve food. We also have the knowledge of how to do it properly.
Food freezing stops bacterial growth, so in theory, frozen food can be used indefinitely. However, we know from experience that quality food degenerates over rime, even frozen.