SSDL/MSL/CSDL file creation

Hello All,

I have found following code in the nopCommerece sample.

I want to know how does SSDL/MSL/CSDL files are created? I know these are from entiry framework. But while code-fisrt development how does it got generated?

I want to know from where the meta data file generated?

 if (InstallerHelper.ConnectionStringIsSet())
            {
                var ecsbuilder = new EntityConnectionStringBuilder();
                ecsbuilder.Provider = "System.Data.SqlClient";
                ecsbuilder.ProviderConnectionString = NopConfig.ConnectionString;
                ecsbuilder.Metadata = @"res://*/Data.NopModel.csdl|res://*/Data.NopModel.ssdl|res://*/Data.NopModel.msl";
                string connectionString = ecsbuilder.ToString();
                InjectionConstructor connectionStringParam = new InjectionConstructor(connectionString);
                //Registering object context
                container.RegisterType<NopObjectContext>(new UnityPerExecutionContextLifetimeManager(), connectionStringParam);
            }

Please guide me