# Core Concepts

Understand the MonetizeKit domain model and evaluation vocabulary before implementation.

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Source: https://learning.monetizekit.app/docs/getting-started/concepts
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Understand the domain model before implementation.

### Customers

Tenant end-users receiving plan-based access.

[Open reference](/docs/api-reference/customers)

### Monetized Customers

The billable unit: distinct customers that received a granted entitlement or had billable activity in a month. You can track unlimited customers; you are billed on Monetized Customers.

[Open reference](/docs/api-reference/usage)

### Plans

Commercial bundles of features and usage limits.

[Open reference](/docs/api-reference/catalog)

### Features

Boolean, string, enum, or numeric capability controls.

[Open reference](/docs/api-reference/catalog)

### Entitlements

Computed access decisions per customer and feature.

[Open reference](/docs/api-reference/entitlements)

### Meters

Usage counters used by limits and billing policies.

[Open reference](/docs/api-reference/usage)

### Credits

Prepaid units with grant/debit lifecycles.

[Open reference](/docs/tools/postman)

### Subscriptions

Binding between customer and active plan versions.

[Open reference](/docs/api-reference/customers)

### Webhooks

Event delivery channel for downstream automations.

[Open reference](/docs/api-reference/webhooks)