Can I buy web hosting without a domain name?

While they both work together, the domain name and the web hosting service are two different things and each function in different ways.
A domain name can be purchased without web hosting. These domains are considered ‘parked’ until such time as their name servers are delegated (or pointed) to a web host. Advanced DNS records of the domain can also be used to point to other servers, although the IP address must be known. However, without a domain name, there is no way to access or lead to the information stored on your web hosting account, and therefore without a domain name, web hosting cannot function.