The kind of services you receive from both is nearly identical. However, the main differences are how you receive the services and the final cost of your services.
With an in-person IT department, you will have a full-service professional on hand to handle your IT needs. You can have the individual come in and service a particular station. They are there to troubleshoot problems and provide you with all your tech assistance. You will also be paying for a full-time professional with a specific skill, which can become expensive quickly.
On the other hand, an off-site managed IT service is a full-service IT company that remotely works with your business. Just about everything you need or require can be handled through remote access. The difference, though, is that instead of paying for a single professional to work full-time in your building, you split the cost of the Charlotte IT Solutions service with the hundreds of other businesses that utilize the company around greater Charlotte and the outstretched communities. This allows you to save a significant amount of money every single year.