DevStudent

MS Visual Studio is a development tool used to create different kinds of applications using technologies present in .NET framework.

MS Blend for Visual Studio is a tool used for designing some application which we develop using MS Visual Studio.

When you install MS Visual Studio 2012 or later versions Blend is installed along with it.

It is specially used in designing windows store apps.
When you are working with windows store apps in visual studio you can open your xaml pages in blend by selecting option Open in blend with a right click on xaml page in solution explorer.