Modern blockchains have the ability to include smart contracts.
Smart contracts are open-source scripts which can be publicly inspected by anyone. DJCoinPrice is such a contract written in solidity.
Unlike Bitcoin, or most other cryptocurrencies whose prices are dictated by market forces (and their vagaries), DJC has a guaranteed price which is enforced by DJCoinPrice.
The algorithm states that the first 20 million DJC will cost one British pound (GBP). Thereafter, the price will rise until the last coin which will cost just over one million pounds.
Because the algorithm is public you are able to inspect it on tronscan.org (or djcoin.com).