What is the definition and classification of skin flaps?

Skin flaps are a portion of skin and subcutaneous connective tissue partially separated from its bed, which is transferred to a nearby area to cover a defect and in which the base or pedicle maintains its vascularization.
Skin flaps are developed from the concept of angiosome, indicating a three-dimensional block of tissue dependent on an artery.
If the artery is cut, the supply can be supplemented by a tortuous anastomotic network that opens up from the angiosomes.