Temporary. the Temp folder is where Windows stores stuff temporarily while performing all sorts of operations from program install to day to day prog opening and file manipulation. tmp is another Windows abbreviation for temporary, and you may find another piece of software creating and using a tmp directory/folder for it's own purposes.
Sounds like a failure to close a process or file in the shutdown process - this sometimes happens, it is a "feature" of the Windows OS that has been with us since Windows 3
For info on minidump files click here