An NFT is a non-fungible token, which is a digital representation of a unique item. This can be anything from artwork or music to a piece of material going through a supply chain.
When an NFT is created, an entry is permanently added to the blockchain. This is similar to adding an entry into a database in the web2 world.
Simply put a signer is just the account that manages transactions.
Networks are different Ethereum environments you can access for a variety of use cases.
The network used in the example above (mumbai) is one of the Polygon testnet networks which we can be used as a sandbox to test actions on the chain before deploying to mainnet (where real asset transactions occur).
Polygon is a side-chain built alongside its parent chain, in our case Ethereum. It has specific benefits such as enhanced speed and reduced cost.
Querying data from projects that have high complexity (such as NFT's) is made easy using the subgraph which leverages a GraphQL endpoint to query data. Our subgraph is setup to query data about any NFT created with the OPENFORMAT protocol. Check out the graph documentation to learn more.
ERC721 is a more complex standard than ERC20, with multiple optional extensions, and is split across a number of contracts. Check out the API Reference to learn more about these.
Ether is the transactional token that facilitates operations on the Ethereum network. All of the programs and services linked with the Ethereum network require computing power (and that computing power is not free). Ether is a form of payment for network participants to execute their requested operations on the network.
Wei is the smallest denomination of ether—the cryptocurrency coin used on the Ethereum network. One ether = 1,000,000,000,000,000,000 wei (10^18). Wei is mostly used when setting monetary values.
Put simply, 1 Gwei is 0.000000001 Ether (1 billionth of an Ether) that is used to measure the cost of transactions on the Ethereum network.