---
title: Serialization
---

The resulting document of a collection is serialized before being written to the file system. This process ensures the document can be stored in a file and later read back into memory. To serialize the document, the resulting object must be serializable, meaning it can only consist of the following types:

- String
- Number
- Boolean
- Null
- Undefined
- Date
- Map
- Set
- BigInt
- Array of serializable types
- Object with serializable values
