Delta
1. The triangular deposits made by the rivers at their mouth form Delta.
2. Deltas are formed in the regions of low tides and coastal plains.
3. Deltas are fertile lands.
4. Ganga and Brahmaputra, Krishna, Kaveri and Mahanadi form delta.
Estuary
1. The sharp edged mouth of rivers, devoid of any deposits is known as Estuary.
2. Regions of high tides and rift valleys witness Estuaries.
3. Estuary does not have fertile lands.
4. Narmada and Tapi rivers form Estuaries.
Regards