---
slug: core-concepts/fragment-types
−section: Core Concepts
−order: 3
+section: Understanding Usable
+order: 4
status: published
description: "How fragment types classify knowledge and when to create a custom type."
---
··· 78 unchanged lines ···
- [Memory fragments](/usable/core-concepts/memory-fragments) are classified by fragment type.
- [Tags and summaries](/usable/core-concepts/tags-and-summaries) add descriptive retrieval signals without changing a fragment’s role.
- [Collections](/usable/core-concepts/collections) curate groups of related fragments.