Absolute Zero: This is theoretically the lowest possible temperature, where all molecular motion would stop. It's like when it gets so cold that even the most die-hard swimmers have left the pool.
Phase Change: A phase change occurs when a substance changes from one state of matter to another due to temperature changes - like water freezing into ice as temperatures drop.
Heat Capacity: This refers to how much heat energy a substance can absorb before its temperature increases significantly. Imagine some people can stay in a chilly pool longer than others because they have higher "heat capacity".