The -R parameter of the ls command prints a recursive listing of a directory’s content, meaning that it

will list not only the files and directories in the current directory, but also the files and directories in

all the subdirectories12. For example, if you have a directory structure like this:

/home/user/ ├── dir1 │ ├── file1 │ └── file2 └── dir2 ├── file3 └── file4

You can use the command ls -R /home/user/ to list all the files and directories recursively, and the

output will look like this:

/home/user/: dir1 dir2

/home/user/dir1: file1 file2

/home/user/dir2: file3 file4

The -R parameter is also known as the --recursive option, which is the long form of the same

parameter12. You can use either -R or --recursive to achieve the same result.

Reference:

Use ls Command Recursively - Linux Handbook

How to List Files Recursively in Linux command line