You can get several informations by accessing the whois of a domain: the header's data (if they're not protected by privacy policy), the server managing the website, the Registrar and, above all else, the domain status.
Here is a short list of several status a domain with .com, .net, org, .info and other generic extensions (gTLD) can assume during its activity.
AddPeriod It's the initial status of the registration. If the registrant erases the domain name during this phase the Registrar can refund the user of the whole amount of the registration.
autoRenewPeriod The domain auto-renews itself and the registrant doesn't have to carry on any action. If the user doesn't want to renew the domain anymore he/she has to contact the Registrar.
Inactive The nameservers are not associated with the domain and the name resolution cannot be processed. If the domain has been in this status for several days the user has to contact the Registrar to check its status. Probably, It will be necessary to provide additional documents.
Ok The domain is active and all the operations can be regularly processed. The user can ask to the Registrar to activate restrictions on the domain, such as clientTransferProhibited, clientDeleteProhibited and clientUpdateProhibited to prevent unathorized transfers,eliminations and updates.
pendingCreate A domain creation request is processing. If the registration was requested for a specific moment of the day the user doesn't have to process any other action. If it takes too long the user needs to contact the Registrar.
pendingDelete The domain has been in redempitionPeriod for 30 days but it will not be restored. It will be in this status for several days and then deleted. If the user wants to keep the domain he/she must contact the Registrar.
pendingRenew A domain renewal is going to be processed. If the user doesn't want to renew the domain he/she has to contact the Registrar.
pendingRestore The domain was in redemptionPeriod and the Registrar is restoring it, after receiving the required documents. If the Registrar does not receive the documents the domain will go back in redemptionPeriod. The user has to wait for 7 days and then check the status with the Registrar.
pendingTransfer The domain transfer is processing or is going to be processed. If no transfer request has been proposed the user must contact the Registrar to stop the process.
pendingUpdate A domain update has been requested. If no request has been proposed the user must contact the Registrar to stop the process.
redemptionPeriod The registrant asked the Registrar to cancel the domain thai is going to be in this status for 30 days. After 5 dadditional days the domain will be canceled and then available for registration again.
renewPeriod The domain has been renewed by the Registrar. It the user doen't want to keep the domain active he/she must contact the Registrar.