A system for releasably connecting a plurality of interchangeable components in an assembly. The system includes a plurality of units and a plurality of interchangeable components capable of being releasably joined to one or more of the plurality of units. The plurality of units further includes a physical connecting system and a magnetic connecting system for relative positioning of at least one of the plurality of units with at least another one of the plurality of units. The physical connecting system includes a set of physical keys. The set of physical keys includes an indentation and projection on the surface of the unit. The magnetic connecting system includes a plurality of magnetic connectors housed in the interior housing of each of the plurality of units.