Creating portable class library in VS2015

Question

Good morning, I'm new to cross-platform programming, so I have a very basic question. I wanted to use Xamarin to create an app for all mobile platforms + desktop versions for mac and windows. I wanted to use Visual Studio 2015. I got stuck at the very start. I wanted to create Class Library (portable), but as I can see, there are few such projects. Here is the screen

My question is: What's the difference between those 5 projects?

There are:

Class Library (Portable) A project for creating a managed class library (.dll) for Windows, Windows Phone and Silverlight apps.

Blank App (Native Portable) A multiproject template for building cross-platform native apps, sharing code using a portable class library. On Visual Studio 2010, the Portable Class Library Tools are required.

Blank App (Xamarin.Forms Portable) A multiproject template for building apps with Xamarin.Forms, sharing code using a portable class library. On Visual Studio 2010, the Portable Class Library Tools are required.

Class Library (Xamarin.Forms Portable) A portable class library for creating shared application code using Xamarin.Forms. On Visual Studio 2010, the Portable Class Library Tools are required.

Answer 1

• Class Library (Portable) - this is just a PCL project [not sure why it's listed twice]
• Blank App (Native Portable) - will create a project for each available platform AND a PCL library for shared code
• Blank App (Forms Portable) - will create a project for each platform, and a PCL library for shared code. Will also install the Forms packages and templates
• Class Library (Forms Portable) - will create just the PCL project with the Forms packages and templates

you probably want to use the first option