A LUT is an ASCII file (Lustre supports the .lut file extension for 1D LUTs and the .3dl file extension for 3D LUTs) that describes specific pixel values used for image data conversion both on input and output. A Print LUT is obtained from your film lab and is updated on a regular basis. You can import a LUT file into Lustre. See Importing a LUT File.
A monitor calibration LUT is applied to the monitor only and affects the display of images, not the image data itself. It is generated from one measure of gamma (white, grey, and black) or a series of progressive measures for each colour channel. The number of steps in the series is defined in the init.config file. See the Autodesk Lustre Software Installation Guide.