TDP is a Teradata product that serves as an interface between CLIv2 and Teradata Database. It executes on the same mainframe as a different job or virtual machine than the application and CLIv2. An individual TDP is associated with one logical Teradata Database; however, any number of TDPs can simultaneously operate and be accessed by CLIv2 on the same mainframe. Each TDP is referred to by the application with an identifier called the TDPid (TDP2, for example) that is unique in a mainframe.
Teradata Database implements the actual relational database that processes requests received from CLIv2 by way of TDP.