CTime, Atime, mtime relations

It is important to differentiate between a file or a directory's change Time (time,ctime), Access time (Access Time,atime), and the modified time (modify Time,mtime).

ctime--in Unix, it is not possible to know the exact creation time of a file. Change Time (CTime) refers to the time when a file or directory's properties (owner, permissions, and so on) have been changed. CTime also changes when the contents of a file change. If a file needs to be backed up, the dump command needs to be ctime. You can use the LS-LC command to view CTime.

atime--access Time (atime) is the time at which a file's data was last accessed. For example, displaying the contents of a file or running a shell script updates the file's atime. You can use the Ls-lu command to view.

mtime--modification Time (mtime) is the time at which the current content of the file was last modified. This is the time displayed in a long list of directories.

In Linux, the status command is displayed 3 times.  Example: The atime of the cat file file will be updated.  $ chmod g+w file CTime will be updated. $ echo "File contents" > File CTime and Mtime will be updated.

CTime, Atime, mtime relations