Someone mentioning about the medieval ‘Kingdom of Cochin’ or later ‘Princely State of Cochin’, refers to a broad area covering parts of Thrissur (including Kodungallur), Palakkad (Chittoor Taluk) and Ernakulam Districts (including areas of Aluva, Parur and Chendamangalam). There is 'Edakochi’, an old locality in the southern end of Kochi; a ‘Kochi Corporation’ spread over 95 Km2 composed of Ernakulam city and rest of Kochi; a ‘Kochi Metropolitan Area’ or ‘Urban Agglomeration’ (UA) of Kochi’ stretching to 500 km²; and a larger ‘Greater Cochin Area’ consisting of 732 km². The regions under UA and Greater Cochin cover several Panchayats and municipalities including Aluva, Parur, Chennamangalam, Nedumbassery etc. I know now it’s really confusing!
- Ernakulam is the new city whereas Kochi is the old city.
- Ernakulam is in the mainland, but Kochi is an Island and harbor.
- Ernakulam is on the east separated from Kochi on the west by backwaters.