system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does freezer burn occur?
gpt
Freezer burn is from sublimation. Ice, when exposed to air can evaporate without melting into water first, this process is called sublimation. Carbon dioxide does this, its why you don't see dry ice melt into a liquid. There is nothing exactly inedible about freezer burned foods they're just oxidized and dried out so they'll taste funny, but they aren't rotting.

You can actually slow down freezer burn from occurring by first properly packaging your foods(vacuum sealing) and secondly by having exposed ice in the freezer. The ice will sublimate and increase the humidity in the freezer so the water in your food wont have to evaporate as much for the freezers humidity to reach equilibrium.