# Places

This document describes the implementation of the Firefox Places component.

It is a robust system to manage History and Bookmarks through a database on the backend side and a model-view-controller system that connects frontend UI user manipulation.

## History and Bookmarks

In Firefox 2, History and Bookmarks used to be kept into separate databases in the Resource Description Framework format ([RDF format]).

However, Firefox 3 implemented the Places system. It has been done due to multiple reasons, such as:

- **Performance**: certain search or maintenance operations were very slow
- **Reliability**: the filesystem facing side of RDF was not so robust, often causing corruption or unexpected states
- **Flexibility**: being able to cross data allows for interesting features, like the Awesome Bar
- **Maintainability**: the future of RDF was unclear, while SQLite is actively maintained and used by a large number of applications

## Where to Start

For the high-level, non-technical summary of how History and Bookmarks works, read {doc}`nontechnical-overview`.
For more specific, technical details of implementation, read {doc}`architecture-overview`.

## Governance

See [Bookmarks & History (Places)](https://firefox-source-docs.mozilla.org/mots/index.html#bookmarks-history)

## Table of Contents

```{toctree}
:maxdepth: 2

nontechnical-overview
architecture-overview
API for managing bookmarks <Bookmarks>
API for managing history <History>
Transactions Manager <PlacesTransactions>
Observer Notifications <notifyObservers>
```

[rdf format]: https://en.wikipedia.org/wiki/Resource_Description_Framework
