This document provides information about key directories and files defined by the Filesystem Hierarchy Standard (FHS) and utilities for locating files on a Linux system. The FHS defines standard locations for different types of files including /bin for essential commands, /etc for host configuration, /lib for libraries, /usr for secondary files, and /var for variable files. Commands like find, locate, whereis, and which can be used to search for files and determine their locations. Find searches file paths and contents, locate uses a database for quick searches, whereis shows possible locations, and which shows the path of executables.