ETH can be traded on the Pulse network and PLS can be traded on the Ethereum network. Bridging can also be done to other smart contract capable networks.
ETH on PulseChain: You can send ETH to the PulseBridge contract on ETH which locks it and issues pETH (pulseETH) on PulseChain at a 1:1 ratio.
PLS on Ethereum: You can send PLS to the ETHbridge contract on PulseChain which locks it and issues ePLS (ethPulse) on the Ethereum network 1:1. This can also work for ERC20s.
Thousands of ERC20 tokens on PulseChain can trade on PulseChain's Uniswap and similar at launch, since Ethereum's state is included.
There will be an ePLS:ETH pair on Uniswap on the Ethereum network & a pETH:PLS pair on Uniswap on the PulseChain network.
There may be ePLS trading pairs on other smart contract enabled chains.
Exchanges may list PLS and any of the thousands of tokens on the PulseChain network.