A basic understanding of DTS begins with an overview of DTS architecture, object hierarchy, supporting files, installation information, and a discussion of programming platforms.
DTS allows the user to program transformations through two different interfaces. Programmers can create and modify DTS packages through an OLE Automation interface implemented in Dtspkg.dll (using any language that supports OLE Automation such as Microsoft® Visual Basic®). Programmers can also write directly to the data pump through a COM interface implemented in Dtspump.dll (using C or C++).
Both interfaces, the package and pump, are extensible. Programmers can create custom tasks for the package interface using Visual Basic or any other language. Programmers can also create custom transforms for the pump interface using C or C++ with Dtspump.h.
In your object browser, there is an OLE Automation package interface called the Microsoft DTSPackage Object Library (DTS) that is implemented by Dtspkg.dll.
There is also an additional interface used by Microsoft ActiveX® scripting tasks (called Microsoft DTSDataPump Scripting Object Library or DTSPump for short) implemented in Dtspump.dll.
DTS is a set of OLE Automated interfaces that use the Microsoft SQL Server™ OLE DB provider to communicate with SQL Server version 7.0.