Salesforce gave us Partial Copy Sandboxes (which I think have been renamed Partial Data Sandboxes) and Sandbox Templates a few releases ago, the former of which is sort've halfway between a Developer Pro sandbox and a Full sandbox, where it doesn't have all your data and can be refreshed more quickly than a full sandbox, and the latter is used to specify the data you want to copy from prod when refreshing a Full or Partial Copy Sandbox.
I wanted to write about some weirdness with Partial Copy Sandboxes.
Partial Copy Sandboxes have some limits, which (as of this posting) are namely a 5 GB total database space limit, and a 10,000 record limit per object.