Explanation:

A front is a boundary between two air masses of different densities. Two major types of fronts are cold fronts and warm fronts.

Cold fronts often come with thunderstorms or other types of extreme weather. They usually move from west to east. Cold fronts move faster than warm fronts because cold air is denser, meaning there are more molecules of material in cold air than in warm air. The cold fronts steep and produces showery and sometimes violent precipitation. Occluded front is formed when cold front overpowers the warm front. Cold, dense air squeezes its way through the warmer, less-dense air, and lifts the warm air. Because air is lifted instead of being pressed down, the movement of a cold front through a warm front is usually called a low-pressure system. Low-pressure systems often cause severe rainfall or thunderstorms.

Warm fronts usually show up on the tail end of precipitation and fog. As they overtake cold air masses, warm fronts move slowly, usually from north to south. Because warm fronts aren't as dense or powerful as cold fronts, they bring more moderate and long-lasting weather patterns. Warm fronts are often associated with high-pressure systems, where warm air is pressed close to the ground. High-pressure systems usually indicate calm, clear weather.