# Essentials

### OVER SDK

The OVER SDK allows you to publish content using all the features of Unity. It also gives you the possibility, through a layer based on a node system, to develop experiences without writing code.

The basic structure is the [OvrNode](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode) which has different behaviors according to the functionality it performs.

All [OvrNodes](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode) have an editable ID – a list of nodes that are executed before their main function, and a list of nodes that are executed after their main function.\
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The primary function will be shown in the center of the [OvrNode](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode) component.

![](https://content.gitbook.com/content/6xdubHTzJACGqFIM7yJy/blobs/yiz8rMBLWYbc9rcPCZtP/Immagine%202022-04-29%20164710.png)

Thanks to the [OvrVariable](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/broken-reference) you'll be able to perform calculations, write texts, and control behaviors.

![](https://content.gitbook.com/content/6xdubHTzJACGqFIM7yJy/blobs/bw81js6rdafIHymyv3uq/Immagine%202022-04-29%20170520.png)

Finally, through [Triggers](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/broken-reference), it is possible to execute multiple [OvrNodes](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode) which execute other [OvrNodes](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode), according to the **Pre/Post Execution Nodes** assigned. The succession of these executions allows the operation of many dynamics; from the simplest, such as changing the color of a light, to the most complex, such as creating a fully working game.

### DEMO

Inside the OVER SDK you will find a Demo Scene that will help you to understand the use of [OvrNodes](https://docs.overthereality.ai/over-sdk-manual/ovr-component-system-ancient-legacy/nodes/ovrnode) to create a mini-game. Moreover, the demo acts as a guide on to how to organize the elements in the scene to keep all the necessary elements ordered for the realization of a project. Specifically, it proposes the creation of a new object for each micro feature created.

![](https://content.gitbook.com/content/6xdubHTzJACGqFIM7yJy/blobs/IQgOejzb8OJz7EibZktG/Immagine%202022-04-29%20165013.png)