Updates plugins user guide for marketplace providers (#923)

* update plugins user guide for marketplace providers

* Incorporate feedback

* Update installing-plugins-via-marketplace.md

* update screenshots

* fix typo

* crop image

docs/developer-docs/latest/plugins/upload.md

@@ -6,7 +6,7 @@ canonicalUrl: https://docs.strapi.io/developer-docs/latest/plugins/upload.html
 
 # Upload
 
-Thanks to the plugin `Upload`, you can upload any kind of file on your server or external providers such as **AWS S3**.
+The `Upload` plugin is used to implement the Media Library available in the admin panel. With it you can upload any kind of file on your server or external providers such as **AWS S3**.
 
 ## Configuration
 

docs/user-docs/latest/plugins/installing-plugins-via-marketplace.md

@@ -4,41 +4,44 @@ description: Instructions to install new plugins in a Strapi application via the
 canonicalUrl: https://docs.strapi.io/user-docs/latest/plugins/installing-plugins-via-marketplace.html
 ---
 
-# Managing Marketplace plugins
+# Using the Marketplace
 
-The Marketplace is where users can find additional plugins to customize Strapi applications. The Marketplace is located in the admin panel, indicated by ![Marketplace icon](../assets/icons/marketplace.svg) _Marketplace_. In the Marketplace, users can browse or search for plugins, link to detailed plugin descriptions and submit new plugins. This documentation describes how to navigate the Marketplace and how to install Marketplace plugins.
+The Marketplace is where users can find additional plugins to customize Strapi applications, and additional [providers](./introduction-to-plugins.html#providers) to extend plugins. The Marketplace is located in the admin panel, indicated by ![Marketplace icon](../assets/icons/marketplace.svg) _Marketplace_. In the Marketplace, users can browse or search for plugins and providers, link to detailed descriptions for each, and submit new plugins and providers.
 
  ::: strapi In-app Marketplace vs. Market website
-The Marketplace in the admin panel only displays v4 plugins, but all plugins for all Strapi versions are discoverable in the [Strapi Market](https://market.strapi.io). Keep in mind that v3 and v4 plugins are not cross-compatible.
+The Marketplace in the admin panel only displays v4 plugins, but all plugins for all Strapi versions are discoverable in the [Strapi Market](https://market.strapi.io). 
+
+Keep in mind that v3 and v4 plugins are not cross-compatible, but that providers are compatible both with v3 and v4 plugins.
 :::
 
 ![The Marketplace interface](../assets/plugins/marketplace-v4.png)
 
-Plugins are displayed on individual cards containing:
+The Plugins and Providers tabs display each plugin/provider on individual cards containing:
 
-- the plugin name, sometimes followed by either of the following badges:
-  - ![made by Strapi icon](../assets/icons/official-market.svg) to indicate the plugin is made by Strapi,
-  - ![verified by Strapi icon](../assets/icons/verified-marketplace.svg) to indicate the plugin was verified by Strapi.
-- the plugin description
+- their name, sometimes followed by either of the following badges:
+  - ![maintained by Strapi icon](../assets/icons/official-market.svg) to indicate it is made by Strapi,
+  - ![verified by Strapi icon](../assets/icons/verified-marketplace.svg) to indicate it was verified by Strapi.
+- the description
 - a **Learn more** button for additional information, including detailed implementation instructions
-- a **Copy install command** button to copy the plugin installation command to the local clipboard
+- a **Copy install command** button to copy the installation command to the local clipboard
 
-In the top right corner of the Marketplace, the **Submit your plugin** button redirects to the Strapi Market where it is possible to submit your own plugin.
+In the top right corner of the Marketplace, the **Submit your plugin** button redirects to the Strapi Market where it is possible to submit your own plugin and provider.
 
 ::: tip
-The search bar displays incremental search results based on the plugin name and description.
+The search bar displays incremental search results based on the plugin/provider name and description.
 :::
 
-## Installing Marketplace plugins
+## Installing Marketplace plugins and providers
+
+::: note
+Marketplace plugins and providers are installed and deleted from the user's terminal ([see Developer Documentation](/developer-docs/latest/developer-resources/cli/CLI.md)).
+:::
 
-To install a new plugin via the Marketplace:
+To install a new plugin or provider via the Marketplace:
 
 1. Go to the ![Marketplace icon](../assets/icons/marketplace.svg) Marketplace.
-2. Choose an available plugin and click on the **Copy install command** button.
+2. Choose the **Plugins** tab to browse available plugins or the **Providers** tab to browse available providers.
+3. Choose an available plugin/provider and click on the **Copy install command** button.
 3. Switch to your terminal and navigate to the Strapi application directory.
 4. Paste and run the copied install command.
-5. Follow any plugin-specific implementation instructions.
-
-::: note
-Marketplace plugins are installed and deleted from the user's terminal ([see Developer Documentation](/developer-docs/latest/developer-resources/cli/CLI.md)).
-:::
+5. Follow any plugin/provider-specific implementation instructions.

docs/user-docs/latest/plugins/introduction-to-plugins.md

@@ -6,15 +6,31 @@ canonicalUrl: https://docs.strapi.io/user-docs/latest/plugins/introduction-to-pl
 
 # Introduction to plugins
 
-Strapi is built around different types of plugins. Core plugins are essential for your Strapi application to function, and therefore cannot be deactivated. Pre-installed plugins, such as Internationalization, are installed in a default Strapi application. Additional plugins that extend and customize Strapi applications are available in the [Marketplace](../plugins/installing-plugins-via-marketplace.md).
+Strapi is built around different types of plugins. Every default Strapi application comes with the following pre-installed plugins:
 
-::: note
-Core plugins which include the Content Manager and the Content-type Builder are documented in their own sections of the user guide as they are quite specific (see [Introduction to the Content Manager](../content-manager/introduction-to-content-manager.md) and [Introduction to the Content-type Builder](../content-types-builder/introduction-to-content-types-builder.md)). This Plugins section focuses on how to manage plugins in general and provides documentation for the other, non-core plugins.
-:::
+* Content Manager (see [Introduction to the Content Manager](../content-manager/introduction-to-content-manager.md))
+* Content Type Builder (see [Introduction to the Content-type Builder](../content-types-builder/introduction-to-content-types-builder.md))
+* Email
+* Media Library (implemented via the [Upload plugin](../../../developer-docs/latest/plugins/upload.html))
+* Internationalization
+* Roles and Permissions
 
- From the admin panel, administrators are allowed to:
+These plugins are essential for your Strapi application to function and cannot be uninstalled.
 
-- discover additional plugins in the ![Marketplace icon](../assets/icons/marketplace.svg) _Marketplace_ (see [Managing Marketplace plugins](/user-docs/latest/plugins/installing-plugins-via-marketplace.md))
-- review the currently installed plugins in ![Plugins icon](../assets/icons/plugins.svg) _Plugins_
+Additional plugins that you can use to extend and customize your Strapi applications are available in the [Marketplace](../plugins/installing-plugins-via-marketplace.md). This section focuses on how to install and manage these additional plugins.
+
+From the admin panel, administrators are allowed to:
+
+- discover additional plugins and [providers](#providers) in the ![Marketplace icon](../assets/icons/marketplace.svg) _Marketplace_ (see [Managing Marketplace plugins](/user-docs/latest/plugins/installing-plugins-via-marketplace.md))
+- review the currently installed plugins and [providers](#providers) in ![Plugins icon](../assets/icons/plugins.svg) _Plugins_
 
 ![Plugins settings](../assets/plugins/plugins-settings.png)
+
+## Providers
+
+Some plugins can be further extended through the configuration of _providers_, packages designed to be used on top of an existing plugin and add a specific integration to it. For example, you can use the AWS S3 provider to extend the Media Library plugin and store files in your S3 bucket rather than locally on your server.
+
+Currently, the only plugins designed to work with providers are the:
+
+* [Email plugin](../../../developer-docs/latest/plugins/email.html#configure-the-plugin), and
+* [Media Library plugin](../../../developer-docs/latest/plugins/upload.html#using-a-provider) (implemented via the [Upload plugin](../../../developer-docs/latest/plugins/upload.html)).