In each system, each caste (jati) - birth-unit - is an endogamous group into which one is born into and will marry within. There are approximately 3,000 jatis in contemporary society.
By contrast, varna is the typical functional division of an advanced society. It is one of the four large caste groups (Brahman, Kshatriya, Vaishya, and Shudra) from which most jatis are believed to derive.
"While the term varna refers to the fours different classes in society, the term jati refers to the different endogamous sections of the Hindu Society which is known as castes." ("An Introduction to Hinduism", Gavin Flood.)


More about varna
Varna literally means "color". It refers to the distinct qualities (guna) that the four functional classes possess in their hearts and minds. There are four different qualities of human beings - white, red, yellow, black.

White (sattva = truthful) represents the quality of purity, love, faith and detachment. Those belonging to this color seek true knowledge and often exist in ones with spiritual temperament. Those that belong to this color, belong to the Brahman class.

Red (rajas = energetic) represents the quality of action, will, aggression, and energy. Those belonging to this color seek honor, power, and status and exist in people with martial and political temperament. Those that belong to this color belong to the Kshatriya class.

Yellow (rajas) represents the same quality as the red color but those in this quality seek communication, interchange, trade, and business instead. This color exists in those of commercial temperament. They make up the Vaishya class.

Black (tamas = inert, solid) represents quality of ignorance, inertia, and dullness. Those belonging to this color are dependent on the rest of the world for motivation and seek nothing. They exist in those of the servile disposition and make up the Shudra class.


Varna also means "veil". It shows the four different ways in which the Divine Self is hidden in human beings. By this, it refers to the ways in which his four body parts make up the four classes, depending on the nature or values that the human holds. The Brahmans hold spiritual and intellectual values and are in charge of teaching the Vedic Sanskrit, thus are made up of his head. The Kshatryas are the warriors that protect the countries and thus are made up of his arms. The Vaishyas are the farmers and merchants in the production nature and thus are made up of his belly and the Shudras are the laborers who perform menial chores and thus are made up of his legs.