App / Add-in questions

Question

I am a new user of SharePoint, and I am currently learning the App development model. I have some questions for SharePoint Apps specialists.

1. When a site owner download and install an app on his web site, do users see this app and can use it ? Or do they have to install the app on their instance ?

2. I red it is possible to make CRUD operations using CSOM. So do I have to conclude it is possible to create a list on the SharePoint farm from a SharePoint-Hosted app using CSOM ?

3. I also red an article about scope of app permissions. So there are four different scopes : Tenancy, Site collection, Web and List. Can I have more informations about Tenancy scope ? Because I did't understand this kind of scope.

Thanks in advance.

Answer 1

1. Once it's installed by owners, it is available to all users and they can use it.

2. Yes, you can do CRUD operations using CSOM. Yes, you can create list from sharepoint hosted app.

   Reference - Create List In SharePoint Using Sharepoint Hosted App

3. From Tenancies and deployment scopes for SharePoint Add-ins

   A SharePoint tenancy is a set of site collections in either a SharePoint farm or in SharePoint Online. In SharePoint Online, the site collections belong to a single customer account. In a SharePoint farm, the site collections can be all the site collections in a SharePoint web application or a subset of them, or it can be a set of site collections from across multiple web applications in the farm.

   So, if your app permission has tenant scope, then you can do CRUD operations at the tenant level for example like Create/Delete site collections.