Modular cabinetry is standardized, singular cabinet boxes that are affixed to each other and the wall to create a long bank or section of cabinets. When uninstalled and removed from the wall they are complete stand-alone cabinet boxes no longer than 5 feet. They usually have one or two doors or drawers. You can easily determine if your cabinets are modular by finding seams between the cabinet boxes. In most cases, you can look underneath the upper cabinet boxes and see gaps or spaces in between the cabinet boxes. To inspect lower cabinets, you can feel underneath the cabinet, by the toekick, and feel the gaps in between the cabinets. If your cabinets are custom or older than 1990, you may have non-modular cabinetry.