Polygon is essentially a 'Layer 2 network' built on the Ethereum blockchain to reduce the traffic load on the main blockchain.
'Layer 2' also known as 'Data Link Layer' which is second layer of seven layers of the OSI (Open System Interconnection: OSI) model of computer networking. It is a protocol layer that transfers data between nodes located on a network segment of the physical layer.
The high traffic load on the Ethereum blockchain with the addition of a large number of users prompted the creation of a 'Layer 2' network such as Polygon.
In addition to being a blockchain network, Polygon also has an indigenous crypto- currency token MATIC.
Recently, leading investment firms including Sequoia Capital India, SoftBank Vision Fund II and Tiger Global made the largest ever Indian blockchain venture investment of $450 million in Polygon.