Iota gave a completely alternative interpretation to the Blockchain: instead of using a binary system (0 = False, 1 = true) they decided to use a ternary system, more precisely a balanced ternary system. Iin addition to the values 0 and 1, IOTA added the value -1 which represents an undefined variable; this means that we don't know if it is true or false.
In practice, this how the Tangle works: each transaction to be stored on the BC, in order to be transcribed (and not validated) must validate two previous transactions.
To confirm that the transactions are correctly validated, Iota has set up the Coordinator, able to create check-points, as since there are still "few" transactions, any Hacker could sneak into the network and validate as correct transactions some transactions that are not. For example, the so called “double expense”.
The balanced ternary validation method, to transcribe the transaction must validate 2 previous transactions: one recent and one older. The problem arises when the past transactions are few because the system would always and only rely on that as it is the most reliable.
To avoid this situation, the IOTA developers have set up a coordinator, managed directly by the company, who establishes checkpoints. These checkpoints are controlled transactions that serve to increase reliable past transactions.
It is evident that in this way the system is absolutely not decentralized, on the contrary, quite the opposite: to instill security in the system it is centralized as all the registrations are filtered by the coordinator.
Iota plans to remove the coordinator in order to get a real decentralized Blockchain.
The removal of the coordinator takes the picturesque name of coordicide and the White Paper is available on the website.
The Coordicide is divided into 3 steps, which take their name from the honey manufacturing stages by bees.
Pollen - Nectar - Honey
The pollen phase has already started in June of this year, while the Nectar phase will start shortly.
In the nectar phase, network users will be able to "create nectar" by reporting bugs within the network.
The honey phase can be defined as a provisional mainnet in order to test the total absence of the Coordinator.
The final mainnet is scheduled for early 2021
Through this interpretation of the blockchain the scalability problem is solved, in fact it works exactly the opposite of the BTC Blockchain. The greater the transactions, the greater the validations and consequently it becomes faster because it is not necessary to solve an algorithm that is based on the problem of the Byzantine Generals.
With the completion of the Chrysalis phase 1, IOTA's testnet reached a peak of 1500 transactions per second.
Well we have come to Iota 2.0, with the exclusion of the coordinator.
Still the test phases are proceeding and in parallel also the development of the potential of the network, in fact it seems to be started the research to be able to tokenize on the Tangle.