# Machine data

Machine data is the foundation for any data-driven analysis in manufacturing. In this section, you'll learn how machine data is created, what it tells you, and where its limitations lie.

## From machine to analysis

Every production line consists of components controlled by controllers. These controllers (PLCs, sensors, gateways) are the [data sources](https://docs.enlyze.com/en/concepts/understanding-machine-data/data-sources) from which ENLYZE reads data.

From these data sources, ENLYZE selectively picks [variables](https://docs.enlyze.com/en/concepts/understanding-machine-data/variables-and-time-series) and records them as time series. This creates a continuous picture of what happens on the machine.

Machine data alone, however, only shows the **how** of production: speeds, temperatures, pressures. For the **what** (which product, which order), you need the [production context](https://docs.enlyze.com/en/concepts/production-context), which is established through order data from the ERP or MES system.

## Three tiers of production data

| Tier                   | Content                                                         | Source                 |
| ---------------------- | --------------------------------------------------------------- | ---------------------- |
| **Data sources**       | Controllers, sensors, gateways                                  | Shop floor (physical)  |
| **Machine data**       | Time series from data sources (temperatures, pressures, speeds) | ENLYZE via edge device |
| **Production context** | Orders, products, target values, time ranges                    | ERP/MES system         |

The combination of machine data and production context enables analyses such as OEE calculation, target-actual comparisons, product analysis, and energy evaluations.

## Topics in this section

* [**Data sources**](https://docs.enlyze.com/en/concepts/understanding-machine-data/data-sources): Where machine data comes from and what types exist.
* [**Variables & time series**](https://docs.enlyze.com/en/concepts/understanding-machine-data/variables-and-time-series): What is recorded and how time series are created.