# Concepts

Every word is defined once here.

| Word | Meaning |
|---|---|
| **Sandbox** | A full Linux VM with its own kernel and disk |
| **Sleep** | Save memory and disk, and release RAM. Billed like running. Programs keep their state |
| **Stop** | Save the disk and release the machine. Not billed. Memory is dropped |
| **Resume** | Start a stopped sandbox again |
| **Wake** | Bring a sleeping sandbox back |
| **Fork** | Make a new sandbox that copies another, with new identity |
| **Snapshot** | A saved state, with disk and optionally memory |
| **Template** | A named, versioned snapshot for starting new sandboxes |
| **Environment** | Variables, files and repositories a sandbox starts with |
| **Tier** | Shared or Spot, at the same price: Spot can be preempted |
| **Location** | Where a sandbox runs: always the EU region, at a site HareBox chooses in an EU country (France at launch) |
| **Fleet** | A group of sandboxes held at a desired size |
| **Budget** | A dollar limit with an action, such as sleep or stop |
| **Condition** | A flag on a state, such as `migrating` or `nested_active` |

The same state names are used in the API, CLI, dashboard, webhooks and logs. See [Lifecycle](../guides/lifecycle.html).