The difference between a log file, a text file and a data file is that a log file is generated automatically to keep track of some specific application, a text file is created by the user in a word processor, and a data file stores data pertaining to a specific application for later use. There may be various other scenarios as well but, generally, all these data and log files are text files. As a tester, you may have to deal with the large-sized data files generated as the output of some process, and need to validate a particular attribute present in those files.As a developer, you may have to deal with huge application log files or application source code files.
