Can I Unstake my ETH?

Could you please clarify for me: Is it possible for me to unstake my ETH? I'm somewhat unfamiliar with the staking process and its intricacies. Would I be able to unlock my staked ETH at any given time, or are there specific conditions or periods I need to be aware of? Furthermore, what would be the procedure for doing so? Would it involve any fees or penalties? It would be greatly appreciated if you could provide some insight into this matter. Thank you in advance for your assistance.