Why are there many files with file extension .chk existing in the hard disk?

There are many files with file extension .chk existing in the hard disk. (For example: File000.chk, File001.chk etc)

These files are created when Scan Disk error checking is carried out.
In the process of recovering any damaged file, the file is saved in the file name with the .chk extension (for example: File000.chk and File0001.chk).
If these files are not required, they can be deleted manually.