> Portal Navigation:
> 
> - Append `.md` to any URL under `https://dev.wix.com/docs/` to get its markdown version.
> - Pages are either content pages (article or reference text) or menu pages (a list of links to child pages).
> - To get a menu page, truncate any URL to a parent path and append `.md` (e.g. `https://dev.wix.com/docs/sdk.md`, `https://dev.wix.com/docs/sdk/core-modules.md`).
> - Top-level index of all portals: https://dev.wix.com/docs/llms.txt
> - Full concatenated docs: https://dev.wix.com/docs/llms-full.txt

## Resource: Glossary

## Article: Glossary

## Article Link: https://dev.wix.com/docs/develop-websites-sdk/get-started/overview/glossary.md

## Article Content:

# Glossary

## $w

$w is the selector syntax you use to select elements in code (for example, `$w('#myButton')`). After selecting an element, use APIs to work with its properties and functions.

## Blocks

[Wix Blocks](https://support.wix.com/en/article/creating-a-velo-package-3964385) allows you to build [apps](https://dev.wix.com/docs/build-apps/develop-your-app/frameworks/wix-blocks/get-started/a-blocks-app-workflow.md), and reuse your code across multiple Wix sites.

## CMS role

Together with [collection permissions](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/work-with-data/introduction/about-collections.md#permissions), [CMS roles](https://support.wix.com/en/article/cms-formerly-content-manager-creating-custom-roles-and-permissions) give you control over which visitors are allowed to interact with the data in your collections and what they're allowed to do. Every person that visits your site falls into one of 4 roles: admin, site member author, site member, and anyone. You can assign specific permissions to each role.

## Database collection

A [database collection](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/work-with-data/introduction/about-collections.md) is a table used on a Wix site. Each row is an item, and each column is a field, including:

- [System fields](https://support.wix.com/en/article/about-database-collections#system-fields): Auto-added, hidden, non-editable fields, including ID, Date Created, Last Updated and Owner fields.
- [Primary field](https://support.wix.com/en/article/cms-using-reference-fields-to-display-content-from-multiple-collections): Text field used for references between collections, marked with a lock icon. Default is Title, but any text field can be set as the primary field.
- Field ID: Immutable identifier used in code for a field, different from the Field Name shown in the UI.

You can connect elements in your site to fields in your collection using [connecting to data](https://support.wix.com/en/article/connecting-page-elements-to-data) and [datasets](#dataset).

[Permissions](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/work-with-data/introduction/about-collections.md#permissions) control which site [roles](#roles) (Anyone, Site member, Site member author, Admin) can create, read, update, and delete items in a collection. Permissions apply to the collection, not individual fields, and work together with the dataset's [mode](https://support.wix.com/en/article/working-with-dataset-modes-and-collection-permissions).

## Database schema/structure

A [database schema](https://support.wix.com/en/article/about-database-collection-schemas) is the definition of a database's structure. The schema defines which fields are in each of your collections and their [type](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/work-with-data/introduction/about-collection-fields.md#field-types). However, in some cases, your collections can contain fields that aren't part of the schema.

## Dataset

A [dataset](https://support.wix.com/en/article/cms-about-datasets) is a component that connects page elements to your [collections](#database-collection). It selects the collection and controls sorting, filtering, and what elements can do via the [dataset's mode](https://support.wix.com/en/article/working-with-dataset-modes-and-collection-permissions) (Read & Write, Read-only, Write-only). Works on regular and dynamic pages and isn't displayed on the live site.

## Dynamic page

A [dynamic page](https://support.wix.com/en/article/cms-about-dynamic-pages) uses a single layout to display different items from a collection. Content is determined by the page URL - its [prefix](https://support.wix.com/en/article/url-prefixes-and-page-grouping) and dynamic segments are saved on each item as a [calculated field](https://support.wix.com/en/article/about-calculated-fields). There are 2 types of dynamic pages: [dynamic item page](https://support.wix.com/en/article/cms-setting-up-a-dynamic-item-page) and [dynamic list page](https://support.wix.com/en/article/cms-setting-up-a-dynamic-list-page).

## Dynamic page dataset

A [dynamic page dataset](https://support.wix.com/en/article/about-data-binding-and-datasets#about-dynamic-page-datasets) is a component that's added to your page automatically when you create a dynamic page. Like a regular [dataset](#dataset), it enables you to connect the elements on your page to your collections. It also allows you to add more filters and to sort the content on your page.

## Functional testing

With [functional testing](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/test-backend-functions/about-functional-testing.md), you can easily and quickly [test and debug your backend code directly in the code editor](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/test-backend-functions/test-backend-functions-with-functional-testing.md). Functional Testing saves you the time and effort of building your own system for triggering and testing your backend functions.

## HTTP function

An [HTTP function](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/build-a-custom-backend/expose-services/about-custom-site-apis.md) allows you to expose your site's functionality as an HTTP endpoint. Call these endpoints from external services or apps to integrate with your Wix site.

## Hook

A [hook](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/work-with-data/data-api/about-data-hooks.md) runs code before or after certain operations. Use data hooks to intercept collection operations, or router hooks to customize dynamic page data binding.

## Live database

The [live database](https://support.wix.com/en/article/managing-your-sandbox-and-live-data#live-data) is your published site's data storage. It appears on the live site and stores data collected there. You can [sync](https://support.wix.com/en/article/cms-accessing-and-syncing-your-sandbox-and-live-collections) between sandbox and live (copy sandbox to live, or overwrite sandbox with live) from the sandbox.

Sandbox and live aren't always enabled for your collections. Learn more about [sandbox, live collections and syncing](https://support.wix.com/en/article/about-sandbox-and-live-collections-and-syncing).

## Monitoring dashboard

Use the [monitoring dashboard](https://dev.wix.com/docs/develop-websites-sdk/maintain-your-site/monitor-your-site/about-the-monitoring-dashboard.md) to track site performance, especially for backend code and data requests. Access it from Developer Tools in the Code sidebar. You can also use [Wix Logs](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/work-with-wix-logs/about-wix-logs.md) to monitor the site's performance.

## Properties panel

Use the [properties panel](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/developer-environments/ides/code-editor/about-the-properties-events-panel.md) to configure elements, add [event handlers](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/build-a-custom-frontend/event-handlers/about-event-handlers.md) and set default behavior on page load.

## Regular editor

The remote Wix Editor for editing and previewing your site's UI and code, as opposed to the [local editor](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/developer-environments/ides/git-integration/about-the-local-editor.md) when using [Git Integration & Wix CLI](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/developer-environments/ides/git-integration/about-git-integration-with-wix-cli.md).

## Release manager

Use the [Release Manager](https://support.wix.com/en/article/accessing-the-release-manager) to view the current published version and [test site](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/work-with-test-sites/about-test-sites.md), and to create, edit, or delete test versions.

## Repeater

A repeater reuses a single layout for multiple items, where each item has the same layout with different content. Use static content set in the Editor, or connect to the [data in a collection](https://support.wix.com/en/article/displaying-database-content-in-a-repeater) to display data-bound lists.

## Revision

Every time you manually save or publish your site following a change, a new revision of your site is created. You can view and manage your revisions in your [Site History](https://support.wix.com/en/article/viewing-and-managing-your-site-history). You can also create a [test site](https://support.wix.com/en/article/creating-a-test-site) or [monitor Wix Logs](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/work-with-wix-logs/about-wix-logs.md) for a specific revision of your site.

## Router

A [router](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/build-a-custom-backend/routers/about-routers.md) lets you control how your site handles incoming requests and SEO. Customize routing logic and the content returned for specific paths.

## Sandbox database

The [sandbox database](https://support.wix.com/en/article/managing-your-sandbox-and-live-data) is your development data storage. Its data doesn't appear on the published site unless you [sync](https://support.wix.com/en/article/cms-accessing-and-syncing-your-sandbox-and-live-collections) to the [live database](https://support.wix.com/en/article/managing-your-sandbox-and-live-data#live-data). Preview mode updates sandbox data.

Sandbox and live aren't always enabled for your collections. Learn more [here](https://support.wix.com/en/article/about-sandbox-and-live-collections-and-syncing).

## Selector scope

A scope defines which elements you can select with a selector function, such as [$w( )](#w), and how those elements behave when they're selected. Depending on which context you received a selector function from, it will either select from the global scope or the repeated item scope.

## Service plugin

[Service plugins](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/extend-wix-business-solutions/service-plugins/about-service-plugins.md) allow you to extend and customize your site's functionality. You can use [service plugins](https://www.wix.com/velo/reference/spis/getting-started) to inject your own custom logic into a part of an existing, out-of-the-box app's flow. You can also use service plugins to integrate with 3rd-party services so that your Wix site and the external services can communicate seamlessly.

## Sidebar

The [Code sidebar](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/developer-environments/editors/about-development-workspaces.md) shows all of the files that make up your site, including pages, popups, files, routers, and database collections. Working in the sidebar, you can perform a variety of actions that affect your site.

## Sync (copy/overwrite)

[Sync](https://support.wix.com/en/article/cms-accessing-and-syncing-your-sandbox-and-live-collections) allows you to move your data between your [sandbox](https://support.wix.com/en/article/managing-your-sandbox-and-live-data) and [live](https://support.wix.com/en/article/cms-accessing-and-syncing-your-sandbox-and-live-collections#accessing-and-syncing-sandbox-and-live-collections) databases. You can copy selected or all items in a collection from a sandbox collection to the live version of that collection. You can also overwrite a sandbox collection with all the data from the live version, or overwrite all your sandbox collections with the data from their live versions. You can only initiate sync operations from the sandbox database.

Sandbox and live aren't always enabled for your collections. Learn more [about sandbox and live collections](https://support.wix.com/en/article/about-sandbox-and-live-collections-and-syncing).

## Test site

A [test site](https://dev.wix.com/docs/develop-websites-sdk/test-your-site/work-with-test-sites/about-test-sites.md) is a version of your site released to a percentage of visitors so you can validate changes before publishing. Manage test sites in the [Release Manager](https://support.wix.com/en/article/accessing-the-release-manager).

## User input element

[User input elements](https://support.wix.com/en/article/cms-about-user-input-elements) capture and store user data in a collection. Connect them to a [dataset](https://support.wix.com/en/article/cms-about-datasets) with [mode](https://support.wix.com/en/article/working-with-dataset-modes-and-collection-permissions) set to Write-only or Read & Write.

## Validation

Validate data entered via [user input elements](https://support.wix.com/en/article/cms-about-user-input-elements) against your criteria, using either the [settings panel](https://support.wix.com/en/article/validating-user-input-with-the-settings-panel) or [code](https://support.wix.com/en/article/validating-user-input-with-code).

## Web module

[Web modules](https://dev.wix.com/docs/develop-websites-sdk/code-your-site/build-a-custom-backend/web-modules/about-web-modules.md) enable you to write functions in the backend and call them from your frontend code. You import functions from backend web modules into your frontend, and the functions execute on the backend. Wix handles all the all the backend-frontend communication required to enable this access.