Magento terminology
Before you look at Magento themes, it's beneficial to know the difference between what Magento calls vendors and what Magento calls themesĀ and the distinguishing factors of websites and stores.
Magento vendors and themes
According to the official documentation, a Magento theme is a component that provides a visual design for an entire application area using a combination of custom templates, layouts, styles, or images. Themes are implemented by different vendors and are intended to be distributed as additional packages for Magento, similar to other components.
Each vendor can have one or more themes attached to it, so you can develop different themes inside the same vendor:
Each theme can have specific rules and custom layout files providing better flexibility both for administrators and developers. The Magento 2 theme structure can be described as follows:
The way that Magento's theme structure works is quite simple. Each <Vendor>_<Module>...