THandle is a platform-specific type used to represent file,
socket, or thread handles used in the Indy library. On the Linux platform, THandle is declared as a LongWord type for VCL versions prior to VCL 6. For VCL 6, THandle is declared in System.pas. For the Windows platform, THandle is declared as the same type and THandle as declared in Windows.pas for VCL versions prior to VCL 6.