The term for the water vapor in the atmosphere is "humidity." Humidity refers to the amount of water vapor present in the air and is a key factor in determining weather conditions. High humidity levels can make the air feel warmer and more oppressive, while low humidity levels can create a dryer atmosphere. Humidity is typically measured using two primary methods: absolute humidity, which quantifies the actual amount of water vapor, and relative humidity, which compares the current amount of water vapor to the maximum amount the air can hold at a given temperature.