Staking is an alternative way of deciding who gets to make the next block in the chain: the more stake you have in the network, the more likely you are to be selected to create the next block - and when you create a block you get rewards.
If you are selected to create the next block, then you are known as the slot leader, and will receive a monetary reward, intended to incentivize honest participation in the network - but you have to be online to become the slot leader, and what if you can’t be online all the time? Then you can delegate your stake to a stake pool.
There is no minimum ada amount to qualify for staking
Stake pools are run by other users on the network, with the promise of being online all the time to maximize the chances of a stake pool member being chosen as slot leader. If someone in the stake pool is chosen to create the next block, then everyone in the pool shares the reward, and the stake pool owner will get their margin as a bonus reward for running the stake pool and supporting the network.
You can acquire stake by buying ada, but when you delegate your stake your ada stays right where it is - in your wallet!
Because the system is designed so that there are diminishing returns as a stake pool approaches a certain percentage of the total network stake. This promotes decentralization and a competitive stake pool market by incentivizing stakeholders to switch stake pools when their current pool gets too big - so ensuring that the rates that stake pools charge stay competitive as they try and attract new stakeholders.
To enable stakeholders to make the best decisions about where to delegate their stake, a pool-sorting machanism will be available.
Learn about staking on a technical level in the staking FAQ
Find out more about the stake pool strategy in the official IOHK blog post
Find out more about the incentive scheme in the official IOHK blog post