A dedicated server, or computing server, is a server where all the physical resources of the machine are available. Unlike a virtual server, which uses a portion of the resources to run its virtualisation technology, a dedicated server allows you to benefit from all of the machine’s available RAM, storage, and computing power. With cloud computing, we can also define this type of solution as "bare metal", highlighting the physical availability of the machine’s resources, in contrast to standard solutions based on virtual instances.
Your next major concern will be compatibility. It's not a shock that most businesses run on Microsoft Windows and use some form of Microsoft Office. Being able to use common third-party clients such as Microsoft Outlook can often be a concern, and even today, compatibility with Microsoft Outlook isn't necessarily guaranteed. This is especially true when sending and receiving meeting invites. It only takes one garbled meeting invite to realize how frustrating this can be in the real world. Even if using Microsoft Outlook isn't a concern, portability is. If the service is entirely web-based, then is there a means for me to take my email offline and send email when I connect?