There are two ways to use the Data Mapper Runtime.
If you generate a data mapping dll in Liquid Studio, it will copy LiquidTechnologies.DataMapper.Runtime.dll from the Install folder. This is a .Net Framework 4.6.2 dll.
If you generate source code and compile your own data mapping dll, this will pull down the LiquidTechnologies.DataMapper.Runtime Nuget and use the appropriate LiquidTechnologies.DataMapper.Runtime.dll for the .Net version you are using (currently supports: .Net Framework 4.6.2, .Net 8.0, .Net 9.0 or .Net Standard 2.0). These targets are inline with the common Microsoft nugets.
You can easily see which you are using by looking in the Bin folder. If LiquidTechnologies.DataMapper.Runtime.dll is 5MB then it is the .Net Framework 4.6.2 version from the install folder. The Nuget version is only 500KB as all of the dependencies are pulled down in separate Nugets.
The following video shows you how to generate your own data mapping dll using c# in Microsoft Visual Studio:
Generate a C# Data Mapping Project in Liquid Data Mapper