you can see/use them here: https://beeswap.dcity.io/swap?pools
this is a way for people to swap one token for another, using the liquidity provided by people.
for example you can take $10 of DEC and $10 of SPS and add it to the pool, then you would have some shares of that pool, get some rewards, and make it more stable when people go to swap between those, because higher amount of liquidity means a single trade will have lower price impact. Different pools have different token pairs, volume, liquidity, and rewards. It's somewhat new around here, but it's awesome.