How does the greenhouse effect trap the heat?

Visible light passes through the atmosphere readily with little absorption. This light energy hits the surface of different materials and the planet itself. Some of this energy is converted into thermal energy which can more readily be absorbed by the greenhouse gases. Water vapor, the most common greenhouse gas is able to dispel this energy through rain, and the other gases keep us alive and warm through the night. Without greenhouse gases, we would be unable to survive on this planet.