# Single Source of Truth (SSOT) A Single Source of Truth (SSOT) is a *central* location where you aggregate data or metadata about specific information. The idea is to have one reliable source to go to when you need to find *something*. If you have a single source of truth for your pictures, then you only need to check there to find what you need. The two possibilities are: * The single source of truth contains all the data * The single source of truth acts as a reliable index to all the data * For instance, if you have pictures stored on a NAS, on Google Photos, on different offline hard disk, etc then the single source of truth might be a wiki page where you list where each part of your collection is stored Combining both is actually the best approach. You have a central storage location for the information, and if you forget about it or someone else needs to find something, then it's still possible to use the index to quickly find the information. A single source of truth makes it easy to *locate* what you are looking for (i.e., helps with findability).