The term Drainage describes the river system of an area.
Drainage Systems, also known as River Systems, are the patterns formed by the streams, rivers, and lakes in a particular drainage basin.
The Drainage System of India, i.e., the river, is divided into 2 major groups :
1) The Himalayan Rivers.
Mainly it include three rivers, the Indus, the Ganga, and the Brahmaputra. These rivers are long and are joined by many
tributaries. A river along with its tributaries form a river system.
2) The Peninsular Rivers.
The Western Ghats, which runs from north to south close to the western coast, forms the main water divide in Peninsular India.
The major rivers of the Peninsula which flow into the Bay of Bengal include the Mahanadi, the Godavari, the Krishna and the
Kaveri.