Almost everything in Unix is a file!
cat *.log | grep error
File name features since the beginning of Unix
README .bashrc Windows Buglist index.htm index.html index.html.old
A path is a sequence of nested directories with a file or directory at the end, separated by the / character
$ documents/files/my_filwe.txtRelative to the current directory
$ /Start of absolute paths for all files on the system (even for files on removable devices or network shared).