PulseX is the largest Decentralized Exchange "DEX" on PulseChain. It enables you to exchange coins on PulseChain for one another. For example you could swap PulseChain's native token PLS for PulseX's token PLSX. It works like Uniswap on Ethereum.
Every time someone swaps from one coin to another on PulseX, liquidity providers earn fees as a reward. Users can bridge in their ERC20s and pair them with free PRC20s in order to provide liquidity and earn fees. This also backs the value of the PRC20s that they got for free.
The supply is deflationary: PLSX only becomes more rare as 21% of all fees on PulseX get used to buy up the price and burn the freshly bought PLSX.