Sthula Sharira, or gross body, is one of the three types of body as per Hindu teachings. The other two are Sukshma Sharira (subtle body) and Karana Sharira (casual body).
The body is known as Sharira in Hinduism because of its perishable nature.
It is known as Sthula because it is perceivable by the sense organs.
The body is the complex of six tissues – hair, skin, veins, flesh, bones and marrow.
It is made up five elements – earth, water, fire, air and space.
The five elements emanate from prakriti, which is dominated by Tamo guna. In the process of creation, prakriti which has attributes of Sattva, Rajas and Tamas becomes heavily laden with Tamo Guna in response to the desire of Ishavara to initiate creative process.
In panchakarana, each element becomes a composite mixture of itself as well as the other four elements, which results in its grossness. Through this process, the elements are rendered capable of producing gross bodies of human beings, animals, insects etc.
The Sthula Sharira is divided into four categories – those born out of sweat, those born out of egg, those born out of other bodies and those emerging from seeds.
The different types of bodies are vehicles for enjoying the fruits of actions (both good and bad) performed by jivas earlier.
Source - Encyclopedia of Hinduism Volume X page 134 - 135 published by India Heritage Foundation