What are DOTs?
DOT is the native token of the Polkadot network in a similar way that BTC is the native token of Bitcoin or ether is the native token of the Ethereum blockchain.
Alexander testnet DOTs have 15 decimal places, while the smallest unit is called the Planck. Kusama tokens (KSM) have 12 decimal places. You can compare the Planck to satoshis or wei, while the DOT is like a bitcoin or an ether.
The table show as below is the old version.
What are the uses of DOTs?
DOTs serve three key functions in Polkadot, (i) to be used for governance of the network, (ii) to be staked for operation of the network, and (iii) to be bonded to connect a chain to Polkadot as a parachain.
DOTs can also serve ancillary functions by virtue of being a transferrable token. For example, DOTs stored in the Treasury can be sent to teams working on relevant projects for the Polkadot network.
DOTs for governance
The first function of DOTs is to entitle holders to control of the governance of the platform. Some functions which are included under the governance mechanism include determining the fees of the network, the addition or removal of parachains, and exceptional events such as upgrades and fixes to the Polkadot platform.
Polkadot will enable any holder of DOTs to participate in governance. For details on how holders can participate in governance, as well as their rights and responsibilities, see the governance page.
DOTs for consensus
DOTs will be used to facilitate the consensus mechanism that underpins Polkadot. In order for the platform to function and allow for valid transactions to be carried out across parachains, Polkadot will rely on holders of DOTs to play active roles. Participants will put their DOTs at risk (via staking) to perform these functions. The staking of DOTs acts as a disincentive for malicious participants whom will be punished by the network by getting their DOTs slashed. The DOTs required to participate in the network will vary depending on the activity which is being performed, the duration the DOTs will be staked for, and the total number of DOTs staked.
DOTs for bonding
DOTs will have the ability to be bonded for a duration of time in order to add a new parachain to the network. The DOTs will be locked during their bonding period and will be released back to the account that bonded them after the duration of the bond has elapsed and the parachain is removed.
Web3 Foundation will distribute up to 20% of mainnet DOTs prior to network launch in 2019 (see the Light Paper or the Polkadot Network FAQ). As Gavin Wood, one of the project's founders, said in his year-end recap, there may be a generally available public sale for some portion of that amount at some point this year. Subscribe to the Polkadot newsletter on polkadot.network for further updates.
Warning: Mainnet DOT tokens are not transferrable until mainnet launch, expected late 2019. Therefore any transfers of Mainnet DOTs are illegitimate and unauthorized. DOTs can not be moved from a current allocation address. Individuals with an allocation of DOTs who transfer their DOT address to someone else can always keep a copy of their private key, therefore there is extreme risk for individuals participating in transfers of DOTs before mainnet launch.
Testnet dots are freely available now - see below for various ways to obtain them.
DOTs are required to make transactions on the Polkadot network. Testnet DOTs do not have any value beside allowing you to experiment with the network.
Getting testnet DOTs
Also, you can get DOTs by joining the faucet channel on Riot. Simply input
!faucet to know how to use it.
You can make your own DOTs by becoming a validator.
Unlike testnet DOTs, Kusama tokens are not freely given away. Kusama tokens are available via the claims process (if you have already purchased DOTs), the frictional faucet, or via grant request from the Web3 Foundation.