A multi-cache is that takes you to more than one location before reaching the final destination.
Some multi-caches have a container at each stage. Each container but the final one holds information (e.g., coordinates) that you need to find the final container.
Other multi-caches (e.g., offset caches) use stages without containers. The location of the final stage is determined from information found on existing objects (e.g., monuments, plaques, public art).
Also, multi-caches with more than two stages can be either "serial" (only the location of the first stage is known, and each stage provides the location of the next) or "parallel" (the locations of all stages but the final are known, and each stage provides part of the information needed to find the final).