The cat command shows the content of a file (not sure if you know this).
part: the / reflects the root (/) directory (not to be confused with the root home directory, which is /root) and the .bashrc reflects the file.
Most, if not all, Linux distro's have their users dedicated to /home (or, in root's case /root). So the above example will probably give you an error message telling you that the file does not exist at that location:
$ cat /.bashrc
cat: /.bashrc: No such file or directory
Maybe these 2 links will also be of use to you:
- Change Directory (cd) Examples | Unix and Linux Command
- Absloute path vs relative path in Linux