The Subcutaneous tissue is sometimes also called the hypodermis. It is the bottom layer of skin of an animal or plant, right below the dermis, which is below the epidermis.
The diagram is incorrect by a typo error: The stratum germinativum is the stratum granulosum layer, the stratum basale is also called the stratum germinativum. The stratum lucidum is located below the stratum corneum. The stratum spinosum is also the stratum mucosum. Below the basal later is the papilla, then the dermis layers, below that is hypodermis also known as subcutaneous later which is the adipose (fat) location just above the vessels of lymph and veins and arteries, attaching to the muscles. However, adipose can become expansive and encapsulate around vessels of the lymphatic, veins and the arteries.
In humans, this is where the body mostly stores fat cells, called adipocyte, and there are also white blood cells and blood vessels.
The hypodermis also connects the muscles of the body to the skin, with something called deep fascia, or connective tissue.