stSOL is the liquid token that represents your share of the total SOL pool deposited with Lido. As soon as you delegate to the pool, you receive the newly minted stSOL. Over time, as your SOL delegation accrues rewards, the value of your stSOL appreciates. There is no waiting time for receiving stSOL tokens. When a user delegates their SOL tokens they do not need to perform or wait for the completion of any delegation or activation steps, as is the norm in traditional staking. The user can instantly exchange stSOL for SOL at any time in the open market.