Can I send ETH from Arbitrum to Ethereum?

Could you please clarify for me if it's possible to transfer ETH from Arbitrum, which is a scalability solution built on Ethereum, back to the main Ethereum network? I'm a bit confused about the interoperability between these two platforms. Is there a specific process or tool that I need to use to accomplish this transfer? And also, are there any associated fees or risks that I should be aware of? Your expert guidance would be greatly appreciated.