>>29196700
arbitrum is a service which provides something called optimistic rollups. Basically they take ethereum transactions that you want to do, and create poker chips to represent those transactions. They do dozens of transactions with the poker chips, and then at the end of the game when you want to cash out you bring it back to ethereum. This is called "settlement". All these transactions which would have cost thousands of dollars on ethereum are actually just one transaction because you used arbitrum. Beta users like bancor are seeing 50x price reductions for gas fees.
Now, the issue with this is its not decentralized. Arbitrum takes these transactions off the ethereum blockchain, so how do you know it's secure? You know its secure because all the transactions are validated by chainlink node validators. I'm sorry if this sounds complicated but i'm already dumbing it down.
the tldr is that all of these gas fees that people complain about are going away, and a fraction of it will be paid to chainlink nodes instead of ethereum nodes that are getting fat off all this waste.