Ardor is an open source multichain platform that aims to tackle the main issue plaguing blockchains: scalability. Blockchains used today such as bitcoin and ethereum chains face scalability issues such as low transactional throughput and high gas fees. Ardor solves this problem through a parent-child chain system where all transaction processing and network securities are done on the Ardor parent chain while all business-functionality is done on the child chains. Ardor uses Proof of Stake consensus mechanism to secure the network, therefore making the system more energy efficient compared to Proof of Work. 

ARDR is the token for the Ardor parent chain. It is used for forging new blocks where block forgers need to stake a certain amount of ARDR before being able to forge new blocks. There are no new ARDR produced from new blocks, however the forgers are rewarded from transaction fees. Aside from forgers, there are bundlers who take care of bundling the transactions in the child chain before sending to forgers to include in the Ardor parent chain. Bundlers are required to pay ARDR to the forgers. There is a maximum supply of 1 billion ARDR token.