Does my business need a server?
The answer depends on what applications you need to run in your business.
Typically a server is used for local and remote access to: e-mail, line of business applications, network security, and file sharing. If you can move all of the above to the cloud, then the answer is: No you do not need a server.
However, many line of business applications (i.e. accounting software, HR software, workflow software) are still not capable of running from the cloud. In this case, the answer is: Yes you need a server.
Some companies prefer to have both an in-house server, and a service through the cloud. This strategy allows to mitigate the risk of down time. In example, you might move your E-mail server to the cloud and run your line of business application and files from your in-house server. In this way, if one goes down you still have other services functioning.
Cost is also a very important factor in deciding what goes on the cloud and what stays in-house. If your current applications are all cloud ready, than this means you might be able to operate with out the cost associated with running a server in-house. Although, without a server, you would have to sacrifice the security benefits that a server provides. Furthermore, both cloud based and in-house services have a cost associated. Albeit, typically running services from the cloud is less expensive to operate and maintain, than the equivalent service in your in-house server.
For the time being, most companies still need a server in-house to run their business. However, it is becoming more common to see a mixture of cloud base and in-house based server. This mixture appears to be the norm until line of business applications and Local Network security completely migrate to the cloud.