# Form Fundaments [//]: # (AUTO INSERT HEADER PREPUBLISH) Fields are the most fundamental building block of the Form System. They are the basis of both `field`s and `fieldset`s. ## What are fields? Fields are the actual form controls the end user interacts with. They extend the `LionField` class, which on its turn uses the `FormControlMixin`. Fields provide a normalized, predictable API for platform components and customly made form controls. On top of this, they feature: - data synchronization with models - formatting of view values - advanced validation possibilities - creation of advanced user interaction scenarios via `interaction states` - provision of labels, help texts in an easy, declaritive manner - better focus management - accessibility out of the box - advanced styling possibilities: map your own Design System to the internal HTML structure ### Platform wrappers - `LionInput`, a wrapper for `` - `LionTextarea`, a wrapper for `