You can add supported files from your computer to the website and share them so others can download and open the files in desktop applications. When you share CSV files with everyone (public), you can use the URL that appears in the item details page to add the CSV as a web layer. In addition, organizational accounts can add image files and use the URL to show images in web apps, pop-ups, and so on. You need to share the CSV and image files with everyone (public) to see the URL in the item details page.
When you add an item from the web, you are referencing the REST endpoint (URL). The website does not store the item itself. You can reference ArcGIS Server web services, KML, and OGC WMS. You can also reference documents and images stored on the web.
If you need to access your service over HTTPS, add your layer with https.
To find the REST URL of an ArcGIS Server service, open the Services Directory page, http://gisserver:6080/arcgis/rest/services, and browse to the service you want to share. You can then copy the URL from the browser's address bar. Do not append any parameters, such as a token, to the URL.
Adding a URL reference to an existing app is an effective way to share your work with members of your organization and the general public (depending on your sharing privileges). In addition to the URL, you can share other details such as the type of app, its purpose, a summary and description, and a .zip file with the code you used to create the app. As an app developer with an organizational account, you can also register your app with the platform.
Adding an app to ArcGIS Online only adds a reference to your URL; the website does not actually store the app files.
As a developer with an organizational account, you can register your app with the platform to generate an App ID. Use the App ID in your app to collect usage statistics and to allow users to sign in to the platform with OAuth 2.0, a standardized authorization framework. With OAuth 2.0, apps guide the user to sign in to the platform though a platform-hosted login page. It also allows your app to work with user content associated with their organization as well as work with other ArcGIS Online capabilities such as geocoding, routing, and GeoEnrichment. To learn more about authentication and OAuth 2.0, see ArcGIS for Developers.
Before you can register your app, you need to add it to ArcGIS Online. See the section above for details. After you've added it, follow the steps below to register your app and get an app ID and app secret.
If you've added a generic type of app, the app is automatically registered and you see the Registered Info button instead of the Register button. You can view and update the registration information.
Redirect URIs are valid addresses that users of your app can be redirected to after they successfully log in.
Once you've registered your app, you can view registration info, which includes an app ID and an app secret. You can also update the redirect URIs, reset the secret, and unregister the app.
You can view the following details: app ID, app secret, app type, and redirect URIs.
Resetting the app secret will invalidate all existing user and app tokens issued for this app. Users will need to sign in to the app again, and apps configured with the secret may need to be updated.
Your app is no longer registered. You do not need to save the item details page.