---
type: Domain Concept
title: Layer
description: Saved visualization over one Provider and an explicit Channel subset.
tags: [map, layer, presentation]
visibility: public
---

# Meaning

A Layer answers **how selected data is presented on a map**. Data identity and
presentation are deliberately separate.

# Owns

- Name, visibility, ordering, and visual style.
- Color, opacity, labels, clustering, and visualization mode.
- An immutable binding to a resolved [Provider](/catalog/provider.md) and an
  explicit subset of its [Channels](/catalog/channel.md).

# Defaults

Catalog defaults are applied only when a new Layer is created. Later changes to
Data Product or Channel defaults must not silently restyle existing maps.

# Composition

A Layer belongs to one [Map](map.md). Multiple layers may visualize the same
Provider differently without duplicating the underlying data source.