An Integrated Development Environment is a piece of software that facilitates the development of new software via programming languages. It helps by providing a number of tools such as:
There are a number of different integrated development environments for the C# programming language:
Visual Studio is by far the most popular option when it comes to C# IDEs. Visual Studio is Microsofts in house IDE and supports a number of languages including C#, C++, Python and Typescript.
Visual Studio has a community edition which is intended for personal, educational or charity purposes in which case it is free. The installer can be found at https://visualstudio.microsoft.com/vs/community/ .
A popular alternative to Visual Studio, especially from those using a Linux based operating system, is Rider. Rider is developed and maintained by JetBrains who are known for making other IDEs such as IntelliJ IDEA (Java), PyCharm (Python) and GoLand (GoLang).
Information about how to install the Rider IDE can be found at https://www.jetbrains.com/rider/. If you are using Rider for personal use, student or charitable purposes then the professional version is completely free.
It is also worth mentioning that Jetbrains develop a high popular add on for Visual studio called ReSharper which provides information on refactoring C# code.
Although having a similar name to Visual Studio, Visual Studio Code is a lightweight source code editor. VS Code can be modified to perform many of the same actions as a full IDE.
Visual Studio Code can be found here https://code.visualstudio.com/