WHOIS monitors now send email alerts when a Domain's status changes. You can use it to keep a watchful eye on a domain you want to buy as it moves through different stages.
Domain Status change alerts are only sent via email.
Domains go through a life cycle of Active, Expired, Redemption, PendingDelete, and Deleted.
To buy an Active domain, you must reach out to the owner directly or through a broker and negotiate a price. The owner can then transfer the Domain to your account.
When a Domain expires, the owner can still renew it for 30 days. Following this, a 3rd party might purchase it.
If the Domain is neither renewed nor purchased by a 3rd party, it enters the Redemption period after about 45 days. The owner can still renew it by paying a Redemption fee during this phase.
When the Redemption period passes, the Domain enters the Pending Delete stage. No changes can happen to the Domain during this stage.
Typically, the Domain is marked as Deleted after five days, and anybody can purchase it.