> For the complete documentation index, see [llms.txt](https://learn.coremodels.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.coremodels.io/core-concepts.md).

# Core Concepts

Welcome to the Core Concepts page. These are the fundamental building blocks of a schema in CoreModels. Understanding these concepts is key to designing, visualizing, and managing your data structures effectively.

You can also use the [Crash Course](/getting-started/crash-course.md) in order to see live examples of how to setup your model.

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#### Types & Elements

At the heart of your schema is the Type, which serves as a blueprint or template for a data structure. A Type defines the kind of information that can be stored, such as a <mark style="color:$success;">Product</mark> or a <mark style="color:$success;">Blog Post</mark>.

Each Type is composed of Elements, which are the individual fields that hold the actual data.

For example, a <mark style="color:$success;">Product</mark> Type would have Elements like <mark style="color:blue;">ProductName</mark> and <mark style="color:blue;">Price</mark>.

* In SQL, Types are like the tables and Elements are like the Columns.
* In Object Oriented programming languages, types are the classes, and Elements are the properties.
* In Forms, the Type is the whole form, and the Elements are the fields inside that form.
* In Content Management Systems (CMSs). All content types are Types and the fields are the elements, For example a <mark style="color:$success;">Blog Post</mark>, and the fields for <mark style="color:blue;">Title</mark>, <mark style="color:blue;">Body</mark>, and <mark style="color:blue;">Author</mark> are the Elements.

Here are a few more examples:

<figure><img src="/files/wuNpqrjI6cohRtbt5hkZ" alt=""><figcaption><p>Examples of Properties/Elements</p></figcaption></figure>

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#### Taxonomies

Taxonomies are classification systems that help you organize your data into categories.

They can be a simple, flat list of options (like a dropdown menu) or a nested, hierarchical structure with parent and child categories.

You can link a Taxonomy to an Element to ensure users select from a predefined list of choices, guaranteeing data consistency.

For example, a field in a registration form, could require the user to select the value for the <mark style="color:blue;">Job Title</mark> field from a fixed set of options: <mark style="color:purple;">Developer</mark>, <mark style="color:purple;">Product Owner</mark>, <mark style="color:purple;">Designer</mark> etc..

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#### Mixins

Mixins are a flexible way to add metadata or attributes to your <mark style="color:$success;">Types</mark>, <mark style="color:blue;">Elements</mark>, or <mark style="color:purple;">Taxonomies</mark>. They don't contain data themselves but provide information or rules about the data structure.

Think of them like C# attributes or setting a "nullable" checkbox in a database, or any validation rules that goes around a field.

For example, an <mark style="color:blue;">Email</mark> Element in a <mark style="color:$success;">Form</mark> can have a "required" Mixin to mark it as a mandatory field, it also has a special validation (format) to insure having the correct structure for a valid email address.

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#### Relations

Relations define the connections between different Nodes (Types, Elements, Taxonomies) in your schema. They allow you to link one piece of data to another, reflecting real-world connections.

A Relation establishes a clear and structured link from an Element in one Type to an entire record in another Type.

For example, a <mark style="color:$success;">Book</mark> Type could have a <mark style="color:blue;">BookAuthor</mark> Element that has a relation to a separate <mark style="color:$success;">Author</mark> Type.

A <mark style="color:$success;">Scientific Article</mark> can inherit all the elements of <mark style="color:$success;">Article</mark> to reduce duplications and promote reusability.

Read more about composition and inheritance at [Broken mention](broken://pages/2qcJwAY7Ueyd56d8JXOT)&#x20;

Other examples of relations could be:

<figure><img src="/files/gc76ipUbfEWbI5xy8X0s" alt=""><figcaption><p>Examples of Relations</p></figcaption></figure>

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#### Spaces

A Space is the top-level container that holds all the different parts of a project, schema, or content repository. It's a complete, self-contained environment that organizes your Types, Elements, Taxonomies, and other components.

Think of a Space like a dedicated folder or a single application where all the data structures and content for one specific project live. but unlike a simple folder, assets within your system -such as a Type- can belong to more than one Space. This allows for reusability without duplication.

a Space is the technical term for a single schema, and the Core Data Model is the unified structure that is built by connecting multiple Spaces together. Read more at the [Core Data Model](/core-data-model.md).

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### Terminology notes:

#### Nodes & Relations

Since the Types, Elements, Taxonomies and the other CoreModels components are interconnected in a dynamic way, far more agile than Tables or Spreadsheets, they are easier imagined and referred to as *Nodes* in a graph, that are connected by the *relations*. \
So for ease of reference, we refer to Types, Elements, Taxonomies, and any other CoreModels structure that can be connected using relations as **Nodes** that floats in the schema grap&#x68;**.**

#### **Schema.org terms and concepts**

In CoreModels, we adopt some terms from the schema.org catalog:&#x20;

* 'SubClassOf' → '*Inheritance*' Concept (is a).\
  Example: a <mark style="color:$success;">car</mark> is a <mark style="color:$success;">vehicle</mark>, so it inherits all the common properties of a vehicle.
* 'DomainIncludes' → '*Composition*' (has-a).\
  Example: a <mark style="color:$success;">car</mark> has a <mark style="color:blue;">transmission</mark>
* 'RangeIncludes' → '*Applicability*' (can-be).\
  Example: a <mark style="color:blue;">transmission</mark> can be <mark style="color:purple;">manual</mark> or <mark style="color:purple;">automatic</mark>