The key distinction is that PoW is permissionless, whereas PoS is permissioned.
Bitcoin is secured by hashpower, which is produced by physical capital outside the network. Nobody needs to ask for permission to start hashing and trade kilowatts for sats.
PoS networks are secured by on-chain assets. This means you can't "mine" it without first buying tokens from someone who already owns them. You need permission from an existing player in order to start participating.
Another aspect of this is 51% attacks are recoverable for PoW, but are a permanent takeover condition for PoS networks. If a single entity ever accumulates more than half the tokens on a PoS network, they are unassailable.
Bitcoin is secured by hashpower, which is produced by physical capital outside the network. Nobody needs to ask for permission to start hashing and trade kilowatts for sats.
PoS networks are secured by on-chain assets. This means you can't "mine" it without first buying tokens from someone who already owns them. You need permission from an existing player in order to start participating.
Another aspect of this is 51% attacks are recoverable for PoW, but are a permanent takeover condition for PoS networks. If a single entity ever accumulates more than half the tokens on a PoS network, they are unassailable.