Edgeware is currently a standalone chain, or solochain, but may become a parachain on a relay like Polkadot network.
Initially, Edgeware is being launched as an independent chain ("solochain"). This means that EDG will be used as the bonding and reward token for validators.
When Polkadot launches, Edgeware will be eligible to become a parachain. DOTs are used to provide shared security and for inter-parachain communication in the Polkadot Network, so if and when Edgeware becomes a Polkadot parachain, for the duration of that parachain status, it will not have validators for the state of the finality of its own, but rather that validation will happen through the Polkadot relaychain's validator pool. However, EDG will still be used for gas fees, spam prevention, and bonding for on-chain activities (e.g. governance).
In the future, the network may vote to make Edgeware a relay chain, just like Polkadot. In this case, EDG may be used to provide security for child parachains.
Parachain bonding I scheduled for the Fall of 2020 through the London upgrade. As of now the structure for incentives to DOT holders is not yet designed. But before the Polkadot bonding, we will see Edgeware Canary Network bonding to Kusama. So it will be a kind of simulation to parachain bonding to Polkadot. Moreover, the auction(s) is an optional stage for parachain slots as few slots will be offered to the contributors in the ecosystem. Crowdfunding a slot is yet another option.