Can you explain what the .NET Standard specification is and how it is used in development?

.NET Standard is an API specification that defines a set of core libraries available across all .NET implementations (such as .NET Framework, .NET Core, Xamarin). It serves to ensure library compatibility across different .NET platforms.

Using .NET Standard allows developers to create libraries that can be used across various environments without changing the code. The developer selects the version of .NET Standard that corresponds to the minimum API set required for their library.

Thus, .NET Standard simplifies cross-platform development and code reuse.