Wikipedia is right about the fat tissue functions:
Adipose tissue, or fat, is an anatomical term for loose connective tissue composed of adipocytes (Fat cells).
Its main role is to store energy in the form of fat, although it also cushions and insulates the body.
Obesity in animals, including humans, is not dependent on the amount of body weight, but on the amount of body fat – specifically adipose tissue.
In mammals, two types of adipose tissue exist: white adipose tissue (WAT) and brown adipose tissue (BAT).
Adipose tissue is primarily located beneath the skin, but is also found around internal organs.
In the integumentary system, which includes the skin, it accumulates in the deepest level, the subcutaneous layer, providing insulation from heat and cold.
Around organs, it provides protective padding.
It also functions as a reserve of nutrients. https://www.sciencedaily.com/terms/adipose_tissue.htm