You might have heard the terms .NET Framework, .NET Core, .NET 8 or simply .NET, however what is the difference between all of these? To understand this, we need to look at a brief history of .NET.

Microsoft introduced the C# programming language in the early 2000s along with the .NET Framework, and the Visual Studio IDE.

C# and .NET Framework are often associated with each other but they serve distinct purposes. C# is a programming language which can be used for writing applications utilizing the .NET Framework, while the .NET Framework itself is a software development framework.

The .NET Framework can be used for developing applications for Windows only. Which means that the applications developed using the .NET Framework wouldn't work on Linux and macOS.

One important thing to note about the .NET Framework is that it supports multiple programming languages such as F#, Visual Basic and of course C#. In this course we will learn .NET development using C# as it is the most popular and versatile language among these.

The long term goal of Microsoft was to enable cross-platform compatibility - allowing programs written in C# to run on any operating system. Therefore, in 2014, Microsoft introduced .NET Core as a successor to .NET Framework. It was the first official cross-platform framework for C#. With .NET Core it is possible to build applications that can run on Windows, Linux and macOS. In terms of speed, .NET Core is faster and more efficient than the .NET Framework.

.NET Core had multiple releases and new versions up till .NET Core 3.1. However, in 2020, Microsoft released a newer version called NET 5.0 where the "Core" term was dropped. The further releases were NET 5, NET 6 and NET 7 etc.

All of the above versions, namely .NET Framework, .NET Core and .NET are collectively referred to as the .NET Platform or .NET Ecosystem.

To sum up everything, the original release in the .NET Platform was the .NET Framework which was succeeded by .NET Core to support cross-platform development, and later .NET Core was rebranded as .NET. As of now, the latest release in the .NET Platform is .NET 8, which we will be using in this course as it supports all platforms and is the most up to date version of the framework.

Visual Studio is the IDE (Integrated Development Environment) which we will be using for writing and executing C# code.