Differences between .NET 4.0 and .NET 4.5 in High level in .NET

Question

Eager to know Differences between .NET 4.0 and .NET 4.5 in High level in .NET and also differences in ASP.NET, C# also in these frameworks

Answer 1

What is new in .NET Framework 4.5 & What's new and expected in .NET Framework 4.5:

• Support for Windows Runtime
• Support for Metro Style Applications
• Support for Async Programming
• Garbage Collector Improvements
• Faster ASP.NET Startup
• Better Data Access Support
• WebSockets Support
• Workflow Support - BCL Support

differences in ASP.NET in these frameworks

Compare What's New in ASP.NET 4 and Visual Web Developer and What's New in ASP.NET 4.5 and Visual Studio 11 Beta:

Asp.net 4.0

• Web.config File Refactoring
• Extensible Output Caching
• Auto-Start Web Applications
• Permanently Redirecting a Page
• Shrinking Session State
• Expanding the Range of Allowable URLs
• Extensible Request Validation
• Object Caching and Object Caching Extensibility
• Extensible HTML, URL, and HTTP Header Encoding
• Performance Monitoring for Individual Applications in a Single Worker Process
• Multi-Targeting
• etc

And for Asp.net 4.5 there is also a long list of improvements:

• Asynchronously Reading and Writing HTTP Requests and Responses
• Improvements to HttpRequest handling
• Asynchronously flushing a response
• Support for await and Task-Based Asynchronous Modules and Handlers

differences in C# also in these frameworks

Go Through C# 4.0 - New C# Features in the .NET Framework and What's New for Visual C# in Visual Studio 11 Beta.

Edit:
The languages documentation for C# and VB breaking changes:

VB: Visual Basic Breaking Changes in Visual Studio 2012

C#: Visual C# Breaking Changes in Visual Studio 2012

Hope this help you get what are you looking for..