> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nectarclimate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Key concepts

> Understand the building blocks of your utility data: sites, meters, accounts, and bills.

<Tip>
  Need help in this area? See [Methodology FAQ](/platform/methodology/faq).
</Tip>

Before exploring your data in Nectar, it helps to understand how everything is organized. This page explains the key concepts and how they relate to each other.

***

## How your data is organized

Your utility data in Nectar follows a simple hierarchy:

```
Your Company
└── Sites (your buildings and facilities)
    └── Meters (measurement points for each utility)
        └── Bills (monthly statements with usage and charges)
```

### Sites

A **site** is a physical location — a building, warehouse, office, or facility. Sites are the central organizing unit in Nectar. Every meter belongs to a site, and all your analytics roll up to site and portfolio levels.

**Example:** Your headquarters at 123 Main Street is a site. So is your warehouse at 456 Industrial Ave.

**Related docs:** [Sites overview](/platform/sites/overview)

### Meters

A **meter** tracks one type of utility at a site. Each meter measures a specific commodity like electricity, natural gas, or water. A single site might have multiple meters — one for electricity, one for gas, and one for water.

**Example:** Your headquarters might have an electricity meter (tracking kWh) and a natural gas meter (tracking therms).

**Related docs:** [Meters overview](/platform/data-inventory/meters), [Meter detail](/platform/data-inventory/meter-detail)

### Accounts

An **account** is your billing relationship with a utility company, identified by an account number. Accounts are discovered automatically when you connect to a utility portal. One account can have multiple meters.

**Example:** Your PG\&E account #123456789 might include both your electricity and gas service.

**Related docs:** [Accounts overview](/platform/data-inventory/accounts), [Account detail](/platform/data-inventory/account-detail)

### Bills

A **bill** is a single utility statement covering a specific time period. Bills contain usage data (how much you consumed) and charges (how much it cost). Nectar processes bills from connections, uploads, or manual entry.

**Related docs:** [Bills overview](/platform/data-inventory/bills), [Bill detail](/platform/data-inventory/bill-detail)

***

## Usage vs. charges: two types of data

Every bill contains two distinct types of information:

<CardGroup cols={2}>
  <Card title="Usage data" icon="bolt">
    **What you consumed** — measured in physical units like kWh (electricity), therms (gas), or gallons (water). This is the basis for consumption tracking, emissions calculations, and benchmarking.
  </Card>

  <Card title="Charge data" icon="dollar-sign">
    **What you paid** — the dollar amounts on your bill. This includes energy charges, delivery fees, taxes, and credits. Used for cost tracking and budget analysis.
  </Card>
</CardGroup>

<Note>
  Usage and charges don't always move together. You might see high charges with moderate usage (due to demand charges or rate increases) or low charges with high usage (due to credits or promotional rates).
</Note>

***

## Understanding billing periods

The **billing period** is the date range a bill covers. Most utility bills cover about a month, but the exact dates vary by utility and meter read schedule.

### Key dates

| Date           | What it means                                             |
| -------------- | --------------------------------------------------------- |
| **Start date** | First day of service covered by this bill                 |
| **End date**   | Last day of service covered (also called the "bill date") |
| **Due date**   | When payment is expected                                  |

### Why billing periods matter

Billing periods rarely align with calendar months. A bill dated January 20 might cover December 21 – January 20. This is why Nectar [converts billing data to calendar months](/platform/methodology/calendarization) for consistent reporting.

***

## Total charges vs. current charges

Understanding this distinction helps you interpret your bills correctly:

### Total charges

The **full amount due** — what you'd pay to settle the account. Includes new charges plus any previous unpaid balance, minus payments received.

### Current charges

The **cost of this period only** — charges generated by your consumption during this billing period. This is what Nectar uses for analytics to avoid counting carried-over balances.

***

## How connections work

A **connection** links Nectar to a utility provider. Once set up, Nectar automatically collects new bills on a regular schedule.

| Connection type       | How it works                                               |
| --------------------- | ---------------------------------------------------------- |
| **Online connection** | Nectar logs into the utility portal using your credentials |
| **Email connection**  | You forward bill emails to a Nectar email address          |

When a connection discovers new bills, Nectar automatically:

1. Downloads the bill documents
2. Extracts usage, charges, and meter information
3. Matches data to existing meters (or creates new ones)
4. Makes the data available in your dashboard

**Related docs:** [Connections overview](/platform/data-input/connections), [Connection wizard](/platform/data-input/connection-wizard), [Email connections](/platform/data-input/email-connections)

***

## Next steps

<CardGroup cols={2}>
  <Card title="Monthly data calculation" icon="calendar" href="/platform/methodology/calendarization">
    Learn how billing periods become calendar month data
  </Card>

  <Card title="Glossary" icon="book" href="/platform/glossary">
    Look up any term used in Nectar
  </Card>
</CardGroup>