Custom data terminology

Custom data helps you to extend Shopify's data models and create your own by using metafields and metaobjects.

To help you understand some of the terminology used in custom data, review the following list of definitions and terms.

Base value

A base value, such as base color or base pattern, is a field that is part of a standard metaobject entry. The purpose is to link your store information to pre-defined, structured data. For example, you might sell a yellow t-shirt that has the name sunny in your store. By setting the base color to yellow, it ensures your products display correctly in searches and maintains clarity across different selling and advertising platforms.

Category metafield

A category metafield is an attribute related to a particular standard product category in Shopify's product taxonomy. For example, if you add the product category Apparel & Accessories > Clothing > Shirts & Tops, then you can add category metafields for size, neckline, sleeve length type, top length type, age group, fabric, target gender, clothing features, and color. Category metafields have default entries that you can either use as is or customize further. For example, the fabric category metafield has default entries for cotton, silk, denim, and more.

These category metafields can be used in your storefront for customers to find the products they need faster. When you connect the color category metafield to a variant option, you can display variant options as swatches for color options on your storefront product pages.

Default entries

Default entries are pre-defined entries for each category metafield in the Shopify Standard Product Taxonomy. For example, the category metafield color has default entries such as orange, red, black. The size category metafield has default entries such as large, medium, small. You can edit or customize these default entries to make them unique to your brand.

Display name

The label used to find and identify an individual metaobject entry in the entry index. It's automatically assigned to the first text field in a metaobject entry, or autogenerated if there are no text fields in the metaobject definition.

Dynamic source

In the theme editor, a dynamic source is a data type created and stored outside of the editor that can be connected within sections and blocks to add unique content values. Dynamic sources include metafields, metaobjects, resources, and their attributes.


The handle is the unique identifier for a specific metaobject entry. It's the unique part of the path used in the URL to refer to the resource.


Metafields help you to customize the functionality and appearance of your store by letting you save specialized information that isn't usually captured in the Shopify admin. Use metafields to customize your online store with additional product data, such as add product care instructions or to make Shopfiy admin processes more efficient.

Metafield definition

The metafield definition specifies which part of your store a metafield applies to and what values the metafield can have. When you create a metafield definition, you can specify the validation rules for the input of values, such as character limits or minimum and maximum values. Product metafields can also be associated with categories from the Shopify Standard Product Taxonomy so that they display only on products with that category. Learn more about the parts of a metafield definition.

Metafield value

The value that is entered for a metafield definition. A definition is the storage area for one or more values created with it. Product metafield definitions can often hold thousands of metafield values. For example, if you have a definition for product care instructions, then the metafield value is the actual instructions, such as "Dry clean only."


Metaobjects are a flexible way to add a new admin resource to your store by grouping multiple fields into a single structure. For example, this can be information about product highlights. Learn more about adding product highlights with metaobjects.

Metaobject definition

The metaobject definition specifies which part of your store a metaobject applies to and what fields and values the metaobject can have.

When you create a metaobject definition, you can name the fields, set the type, such as text or URL, and set validation rules, such as character limits, for each field in your metaobject. Learn more about building a metaobject.

Metaobject entry

The metaobject entry is the individual instance created from the metaobject definition. If the definition creates the structure of the object, then the entry is the actual content or data for the metaobject. You can create multiple entries from a metaobject definition. These entries can then be used or connected to your store.

For example, you might make a metaobject definition called Product highlights and then create entries from that definition called Sustainability and Comfort. Learn more about creating metaobject definition and entries with a tutorial on adding product highlights.

Namespace and key

The namespace is a container for a group of metafields. Grouping metafields within a namespace prevents your metafields from conflicting with other metafields with the same key name. The key is the name for the metafield.

The namespace and key together help differentiate the context in which a metafield has been created and help identify the metafield in the custom data index.

Shopify Standard Product Taxonomy

Shopify Standard Product Taxonomy is a predefined and standardized list of product categories, attributes, and attribute values.

Shopify Standard Product Taxonomy is used for the following purposes:

  • Unlock product attributes, referred to as category metafields, that map to each product category.
  • Manage your products better within Shopify, for example, as a condition for an automated collection or to help filter your product list.
  • Make it easier to sell products in other channels that require a standardized product category, such as Facebook or Google.
  • Determine the rate at which the product is taxed. Your products might be subject to special rates or exemptions. When a product is categorized correctly, the most accurate tax rate will be collected at checkout.


A metafield definition's underlying data type, such as weight, color, single line text, date, and integer. The type enforces a basic format of what can be entered as a value in that field.

Unstructured metafield

A metafield without a definition. These are metafields typically made by an app. They don’t have all of the validations that a structured metafield might have. Structured metafields are metafields that are created in your store settings. You can migrate unstructured metafields to a definition.

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