Polygon API is a way to connect to Polygon infrastructure to get data sets like reference data or end-of-day market data. Depending on the type of API and technology it’s based on, you can get another set of data for your application. Read the documentation of each API to operate them correctly.
Layer 3 is a logical layer of a blockchain network that’s concentrated around addressing, routing, and prioritizing blockchain data to speed up the whole process of data exchange, decrease the costs of transactions, and protect the interests of participants in any other possible way. Another function of layer 3 solutions is to simplify the “relations” between layer 1 and layer 2 systems ignoring their operating differences.
Polygon data is created via generation of blocks filled with customers’ transactions. Polygon uses Ethereum for validation of their chain.
Polygon Historical data itself can be extracted by Polygon API using Archive Nodes.
No, it doesn’t have an app, but many applications use Polygon for their needs. The main goal of using Polygon is to avoid any scalability issues connected with Ethereum and get a lower transaction price than in the original blockchain. Using Polygon, users can install the connection with any DApp without worrying about network congestion.