Package Files Created by Compiling
To create a package, you compile a source file that has a .dpk extension. The base name of the .dpk file becomes the base name of the files generated by the compiler. For example, if you compile a package source file called traypak.dpk, the compiler creates a package called traypak.bpl.
A successfully compiled package includes .dcp, .dcu and bpl files. For a detailed description of these files, see Packages and standard DLLs.
These files are generated by default in the directories specified in Library page of the Tools > Options > Environment Options > Delphi Options > Library dialog. You can override the default settings by right-clicking the package in the Project Manager and choosing Options to display the Project Options dialog; make any changes on the Directories/Conditionals page.