# Connections

Welcome to a quick guide that will help you grasp the core concepts of connections, nodes, and edges as they apply to our GraphQL API.

**1. What Are They?**

**Connection**: It's the link between data points. In GraphQL, a connection models a one-to-many relationship, and it is the heart of pagination.

**Node**: Represents an individual piece of data in your dataset. Think of nodes as the primary elements you're trying to fetch.

**Edge**: Serves as the bridge between connections and nodes. It contains both the node's data and additional information about the connection, like a cursor for pagination.

**2. Visual Representation**

Imagine a necklace. The necklace itself is the connection. Each bead on it is a node, and the thread passing through each bead is the edge.

**3. Why Use This Model?**

* **Scalability**: This model ensures efficient data fetching, especially when dealing with large datasets.
* **Flexibility**: It supports intricate pagination and data fetching patterns, such as infinite scrolling.
* **Consistency**: It provides a standardized way to interact with varying datasets.

**4. A Simple Query Example**

<pre class="language-graphql"><code class="lang-graphql"><strong>{
</strong>  units(first: 5) {
    edges {
      node {
        id
        name
      }
      cursor
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}
</code></pre>

In this example:

* We're querying a connection called `units` to fetch the first 5 properties.
* Each `edge` contains a `node` (actual property data) and a `cursor` (used for pagination).
* The `pageInfo` gives us details about the pagination status.

**5. Key Concepts Recap**

* **Connection**: The whole dataset or its subset.
* **Node**: Individual data items you're fetching.
* **Edge**: Contains the node and additional info about its position in the dataset.

**6. Best Practices**

* While paginating, always use the cursors provided within edges. Manual modifications can lead to unexpected results.
* Familiarize yourself with the specific fields and data types within nodes relevant to your queries.

You can read more in the specification: [https://relay.dev/graphql/connections.htm](https://relay.dev/graphql/connections.htm)