Why do clouds form before it rains?

Clouds always form before it rains because clouds are actually just a collection of moisture that is made up of water than evaporated from earth. This moisture is then released from the clouds in the form of rain. This makes up the water cycle in which rain water eventually evaporates to form clouds, which results in more rain. 

Clouds form before it rains because when water evaporates those droplets form clouds to hold in the water then when a cloud can not hold any more water it rains