The "Staking" type allows staking-related transactions, but do not confuse a staking proxy with the Controller account. Within the Staking pallet, some transactions must come from the Stash, while others must come from the Controller. The Stash account is meant to stay in cold storage, while the Controller account makes day-to-day transactions like setting session keys or deciding which validators to nominate. The Stash account still needs to make some transactions, though, like bonding extra funds or designating a new Controller. A proxy doesn't change the roles of Stash and Controller accounts but does allow the Stash to be accessed even less frequently by delegating roles of the stash account to the stash proxy account.