If you find a file with the .dat extension on your computer, it is simply a general data file that contains important information about the program that created that particular file.
How to Read and Open .DAT Files in Windows
It can be anything, such as an email attachment (as winmail.dat files), an image or video, a document, or even data, which stores information for software to process. The information in the .dat file can be binary or plain text, but is related to the program that created the file.
In order to read or open a .dat file, you need to know what kind of file it is. Then you need to convert it so that you can open it more easily.
However, such files are not associated with any particular program, so if it is in plain text, you can try opening it with different programs like MS Document or Notepad and others, and it will display the content. Otherwise, you will only see some raw data that you cannot understand unless you are a programmer.