Water. That's right, clouds are made of suspended ice and water. Some of the water is in the form of ice crystals, some of the water is liquid and some water you can't even see but trust me it's there. The invisible form of water is called water vapor which is water in the form of a gas. In fact, you are surrounded by water vapor right now and are breathing it in as we speak.

The reason clouds constantly change shapes is because water is constantly going back and forth from the liquid or solid (ice crystal) phase to the vapor phase. In fact, it's happening right now with the water in the air that's right in front of you.

However, eVAPORation is dominating so the net result is that water is in the gas vapor form. If condensation were dominating, the vapor would condense into tiny liquid droplets suspended in the air...and thus a cloud will form. So, in clouds condensation is dominating over evaporation.

When you see your breathe in the winter time, you have made a cloud...because the water from your breathe has created suspended liquid water and ice particles. But quickly, evaporation wins over and the water goes back to being a vapor...so the cloud disappears.

Although it's not a cloud, there is another way to draw moisture from the air so you can see it. On a humid summer day put a cold glass of lemonade out on the porch. Soon, water will collect on the outside of the glass. That water condensed onto the glass from the air surrounding the glass. It has nothing to do with the lemonade in the glass.

The cool glass took energy away from the air surrounding the glass. The result is that the surface of the glass warms up a little and the air surrounding the glass cools down a little. Now with less energy, the moisture in the air surrounding the glass can't hold the vapor form anymore, but it needs a surface to condense onto. The glass provides that surface and voila! That's how water droplets form on your cold glass of lemonade.