Convert pdb to exr

What is the difference between .pdb and .exr?

Description: Standard data format used by several different programs on Palm-based PDA devices; may store various types of data, such as eBooks, word processing documents, spreadsheets, databases, maps, and image files.; Raster image stored in the OpenEXR format, a high dynamic-range (HDR) image file format developed by Industrial Light & Magic; supports multi-layer images, lossy and lossless compression, and 16-bit and 32-bit pixels; used for storing deep raster images for high-quality graphics; used by raster graphics editing programs and imaging applications.