Can you Unstake ADA?

Can you please clarify for me the process of unstaking ADA? I understand that staking is a way to earn rewards by locking up your ADA tokens in a staking pool, but I'm wondering if there's a specific process I need to follow to unstake them. Do I need to wait a certain period of time before I can withdraw my tokens? Are there any penalties or fees associated with unstaking? I'd appreciate any information you can provide to help me understand the unstaking process for ADA.