--- title: DAMs, systems of record, and how PhotoStructure plays well with others url: https://photostructure.com/guide/system-of-record/ date: 2020-12-07 keywords: system-of-record, sync, sidecars, metadata, deduplication, asset-management, NAS --- PhotoStructure is designed to work smoothly as your only photo and video manager, or as a "friendly sidekick" to other applications that you're already using. This article will discuss why this is an important feature, and how it's implemented. ## 📋 What's a DAM? [Digital asset managers](https://en.wikipedia.org/wiki/Digital_asset_management), or DAMs, assist in the creation, indexing, and sharing of photos, videos, and other file types. DAMs are most often used in commercial settings by corporations, and can be several-thousand-dollar-per-month enterprise software packages. ## 📱 What's an "image organizer"? [Image organizers](https://en.wikipedia.org/wiki/Image_organizer) are much like DAMs but with features more relevant to individual users. Note that there isn't strict agreement across the industry as far as what constitutes an image organizer versus a DAM. Some people and companies even use the terms interchangeably. PhotoStructure is a web-based image organizer that incorporates several features found in DAMs. ## 🎯 What's a "system of record"? Enterprise software architects talk about [systems of record](https://en.wikipedia.org/wiki/System_of_record). The idea is simple: when you've got multiple copies of some bit of data, you need one source that can be relied upon as the "source of truth." Some DAMs and image organizers assume that they are the system of record, and break if external changes are made. ## 🤝 How does PhotoStructure "play well with others"? We recognized early on that there will be applications that have features you don't want to give up, like more advanced image editing, and will want to use these apps in concert with PhotoStructure. PhotoStructure "plays well with other apps" by **never assuming that it is the system of record.** PhotoStructure detects and handles external changes gracefully, and incorporates these changes in your library automatically. ## 🔄 What if I move files around? Many image organizers, like Apple Photos, can break (or require manual "repair" steps) if you add, move, rename, or delete files in your library outside of the app. PhotoStructure, however, was designed to let you move, organize, and edit your files as you see fit. PhotoStructure's "sync" job detects renames, moves, copies, and deletes, and updates your PhotoStructure library to reflect those changes. ## 📝 How does PhotoStructure handle changes made by other apps? When you make changes to your photos or videos within an image organizer, they need to write those changes someplace. This can be in the original file (which can be called a "destructive edit"), or as a series of instructions, possibly stored outside the original file (commonly called "non-destructive edits"). These non-destructive edits are sometimes stored in [sidecar files](https://en.wikipedia.org/wiki/Sidecar_file), which are files that sit in the same directory as the original file, share the same name, and have a file extension of `.xmp`, `.exif`, or `.mie`. PhotoStructure knows how to read many different sidecar formats, and periodically runs a "sync" job to find changes that other apps may have made to your filesystem. Changed files are re-imported into your library. ## 🔀 What if I have more than one copy of something? PhotoStructure will [deduplicate](/faq/what-do-you-mean-by-deduplicate/) assets that are found to have more than one "variant." This de-duplication means that there is always one or more files that represent a given asset. If each file is the same, there's no problem. If these files contain different information, say, different keywords, or different captions, what should happen? PhotoStructure resolves these conflicts by "layering" metadata fields, last-one-in-wins, in order of [file quality and recency](/faq/what-do-you-mean-by-deduplicate/#how-does-photostructure-pick-which-file-to-show). As a concrete example, if you have an original photo, and a downsampled copy of that photo from a Google Takeout, when PhotoStructure imports the file, it will include the metadata from the JSON sidecar in your Takeout, even though the Takeout variant is of lower quality. ## ⚠️ I have photos on my NAS and my Desktop. Anything I should watch out for? Are you editing files on **both** your NAS and your Desktop? For every folder, you need to pick which location is your _system of record_: only make edits there, and synchronize those changes to the other location. If you don't do this, the contents of the two locations will drift out of sync. If you were using your NAS as your backup, _you don't have a backup anymore_: you've got two quasi-similar copies of your stuff.