Cold Front
Cold front explained in an easy to understand way:
Imagine you're at a crowded party trying to find a place to sit, but the couches are already filled with people lounging around. Just like how you might slide onto the floor in front of the couch to claim your spot, a cold front does something similar by sliding under a mass of warm air. The crowded couch is like the warm air, already settled in its place, and you are like the cold front, moving in and finding a position underneath the existing warm mass.
Practice Version
Cold Front: The boundary of a mass of cold air where it slides under a mass of warm air. Cold front. A cold front is when cold air moves in and pushes warm air upward, often causing weather changes like rain or thunderstorms.