# Data

What an app stores and how it reads and writes it: entities, migrations, queries, personal data and location.

| Page | What it covers |
|---|---|
| [Entities, stores and migrations](/docs/data.md) | How you declare the records your app keeps, where they are stored, and how their shape changes over time. |
| [Reads and writes](/docs/reads-and-writes.md) | How a program reads and changes stored records: queries, filters, totals, related records, refused writes and all-or-nothing actions. |
| [Personal data](/docs/personal-data.md) ▲ partly | Your app says which data is about a person, and Jadpo exports it, erases it and deletes it when its time is up. |
| [Geospatial](/docs/geospatial.md) | Geospatial values say where things are, and what is near or inside what, such as the shops within five kilometres of a customer. |