There are three types of recording systems: Video Management Software, Network Video Recorders (NVR), and Cloud service systems. Each one provides some unique capability.
Video Management Software (VMS) is software only that runs on your Windows computer and can be scaled to any size of system.
Network Video Recorder (NVR) is a complete system that includes the computer and software and is typically proprietary and not expandable.
Cloud service provides remote recording (over the Internet) for IP cameras at many different locations.
For more details take a look at our review and comparison of a number of these IP video recording systems.