Domain registrations must be renewed annually, depending on the extension and the registrar that manages it. When a domain is no longer renewed by its current owner, it becomes available for anyone to register.
Domain backorders work like a waiting list so that, if the domain you're interested in expires, the company where you registered the backorder can capture it for you within milliseconds of it becoming available, generally charging a fixed price that includes the domain's one-year registration fee.
At Endominios.com we can help you get a domain in any extension.
So if the domain you're looking for is about to become available for anyone to register, we'll help you get there first. Contact us as soon as possible.