> For the complete documentation index, see [llms.txt](https://code-collective.gitbook.io/launch-flow/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://code-collective.gitbook.io/launch-flow/get-started/core-concepts.md).

# Core concepts

### Launches

A **launch** is a scheduled change with a time attached. Each launch moves through states you can see in the dashboard: *Scheduled* (waiting), *Live* (applied), *Rolled back* (reverted), or *Failed* (something prevented it, see [Troubleshooting](/launch-flow/reference/troubleshooting.md)).

### Snapshots

Before Launch Flow changes anything, it saves a **snapshot** of the original values for prices, that's the existing amount on each product. The snapshot is what makes a clean rollback possible: Launch Flow always knows exactly what to restore.

### Scheduled events

Your plan determines how many launches can be scheduled at once. The Free plan allows **one** scheduled event at a time; paid plans allow more (see [Plans & limits](/launch-flow/reference/plans-and-limits.md)).