Following table shows capabilities of different role types WordPress offers. Here I have listed capabilities unique to the role. Each role inherits all the capabilities from its lower capability roles.
The subscribers are having the lowest capabilities. While the Admins (or Super Admins if multi-site) are having maximum capabilities.
For example: Author's total capabilities = Author's Capabilities + Contributor's Capabilities + Subscriber's Capabilities.
Somebody with access to the site network administration features and all other features.