Java is developed by Sun Microsystems.(Often called Sun Java)
Java is a light weight language and can be run on almost all the OS(it require less hardware)
There is no standard tool available for Java. Although, many third party IDEs are available. E.g. TextPad or Netbean.
Java is a programming language designed to be run on multi platforms and uses a common language which has to be compiled and run on different platforms (e.g. Windows, Mac and Linux).
i.e. Java can be used for writing programs for different operating systems
.NET
Net is developed by Microsoft Corporation
.Net needs a very heavy framework to be installed which has higher Hardware requirements too compared to Java.
A standard development IDE is available for .Net that is Microsoft Visual Studio .NET that allows to program in any .Net language we choose, but has compilers for many different languages that generate a platform specific code (i.e. Microsoft or Windows).
.NET can be used for making any programming language into a Windows Program
.Net is a Framework or programming platform developed by Microsoft Corporation which supports several programming languages including C# (C Sharp), VB.NET, J# and managed C++. It provides a common set of class libraries, which can be accessed from any .NET based programming language. There is no separate set of classes and libraries for each language. If we know any one .NET language, we can write code in any .NET language.
When we write code in any .Net language and compile, it will be converted to an 'Intermediate Language' (Microsoft Intermediate Language - MSIL). So, our compiled executable contains the IL and not really executable machine language. When the .NET application runs, the .NET framework in the target computer take care of the execution. The .NET framework converts the calls to .NET class libraries to the corresponding APIs of the Operating system.
It is Microsoft's application development platform that enables developers to easily create Windows applications, web applications, and web services using several programming languages, and without having to worry about low-level details like memory management and processor-specific instructions.
It is a layer between the operating system and programming language.
What is Visual Studio.NET?
Visual Studio.NET is just an editor, provided by Microsoft to help developers write .NET programs easily. VS.NET editor automatically generates lot of code, allow developers to drag and drop controls to a form, provide short cuts to compile and build the application etc.
Visual Studio is a suite of applications created by Microsoft to give developers a compelling development environment for the Windows and .NET platforms. Visual Studio can be used to write console applications, Windows applications, Windows services, Windows Mobile applications, ASP.NET applications, and ASP.NET web services, using C++, C#, VB.NET, J#, and more.
