With the file extension DMP generally so-called Dumpfiles are marked. Dump is usually a copy of the memory contents of a device. The result of outputting this content to a file is called dullile.
Dump files are usually generated by the operating system automatically after a system crash. These files can be analyzed to find the cause. Dmp is not a real format, but just a memory dump. Therefore, it is important to know who created the file if you want to analyze it.
In general, DMP files can be viewed in a hex editor and, depending on the type, with a developer tool. It should be noted, however, that DMP files can be very large depending on the size of the memory and many editors can not handle files of several GB size. Most DMP files are only interesting for developers.
DMP files are mostly generated by Windows or Visual Studio and may vary in size depending on the setting. In addition to the small memory dump (64 KB size), there is the Kernel Memory Dump and the complete memory dump, the size of which depends on the system's main memory size.
Depending on the type of system crash, often no DMP file is generated. If you look at a blue screen with a percentage below it will generate a DMP file. After several such crashes it is recommended to delete them again. This can be done either through the system cleanup or programs like Pirisoft CCleaner.