What Is Auto-Defrost?

While adding products today, I came across the term "auto-defrost" and I realized that I didn't really understand it! So, I did some (brief) research, and it turns out that this feature is very important, especially when it comes to refrigerators, freezers, and wine coolers. Sometimes, ice builds up on the sides of the cooling/freezing unit, whatever it may be. Before auto-defrost was developed, you had to removed everything inside the refrigerator or freezer, unplug the unit, and wait for the ice to melt. Now, with auto-defrost, the unit automatically warms up a little and melts any frost that may have formed on the sides. The condensation from this frost is then drained through a collecting duct at the back of the unit. It's an amazing concept - one that most people don't even think twice about. Without auto-defrost, foods inside freezers would have ice inside the packaging, adding more necessary heating / cooking time. Additionally, foods could constantly be stuck together! (Think about the Glad commercials - that's exactly what I'm talking about!)