The other common type of low cloud is called a stratus cloud.
These are wide flat clouds that frequently stretch from horizon to horizon.
Stratus clouds commonly form when air is advected
(pushed by the winds) into an area and mild, moist air is forced up
over cooler, dense air until the moistures condenses out to form a thick
blanket of clouds.
Stratus clouds from below
Visible satellite image
IR satellite image
The first satellite image is a visible image using reflected light, the second satellite image is an IR image that mesures thermal energy.