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- In caching we temporarily store information more local (closer proximity) information that we need, with the goal of being able to retrieve it quicker.
- temporary storage, we need to clear the cache and re-populate it when the "source of truth" updates
- In snapshotting, we take a picture of something as it was, and keep that picture, so that regardless of what happens to the subject of the photo, we may always look at our photo to see what that subject looked like at that one point in time.
- long term storage, if the "source of truth" updates, we don't want our snapshot to update
Example
- Browsers cache to reduce network load. An HTTP 304 response is an indication from the server, that what the browser has is not out of date - the browser's cache is good
- Requisition Service currently "snapshots" the list of Orderable IDs that a Requisition has is a Snapshot of the FTAP at the time the Requisition is created (by product of this is that for subsequent retrievals of FTAP, we save a network call to Reference Data service to get the IDs). However the snapshot doesn't extend to the FTAP or Orderable definition (max months of stock, netcontent, etc)
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