# Introduction

NitriteCollection represents a named document collection stored in a Nitrite database. It persists documents in a Nitrite database. It is similar to a table in relational database or a collection in MongoDB.

Each document in a collection is associated with a unique NitriteId. It exposes a set of methods to perform CRUD operations on documents. It also supports indexing and querying. It also supports event based notification on document changes.

NitriteCollection is thread-safe and supports concurrent read and write operations.

A NitriteCollection can be created using Nitrite class. You need to call getCollection() method on Nitrite class to get an instance of a NitriteCollection.

If the collection does not exist, then it will be created automatically. If a collection with the same name already exists, then it will return the existing collection.

Nitrite db = Nitrite.builder()
    .openOrCreate();

NitriteCollection collection = db.getCollection("myCollection");

A collection name cannot be null or empty string. It cannot contains any of the following characters:

• | (pipe)
• : (colon)
• + (plus)

The name also cannot be any of the following reserved words:

• $nitrite_users
• $nitrite_index_meta
• $nitrite_index
• $nitrite_meta_map
• $nitrite_store_info
• $nitrite_catalog