There are Three dirrerent low level clouds Stratocumulus, Stratus, and Cumulus.
stratocumulus
The low-altitude billowy cloud is called cumulus cloud.
A cloud that is known for being low and widespread is a nimbostratus cloud. They are large and wide precipitate clouds that reside at low and medium altitudes.
It means it's a low cloud.
cumulus cloud
Stratus
dead cloud
Nimbostratus is the name of the cloud that can appear at low or mid level and appears as a heavy gray rain cloud.
A stratus cloud
nimbostratus cloud
low type
Nimbostratus
Fog is just a cloud that is low enough to touch the earth's surface. Yea fog is a cloud.