What does the 'mv' command do?

The 'mv' command is primarily used for two functions: moving files and directories from one location to another and renaming them. When you issue a command like 'mv file1.txt /new_directory/', it relocates 'file1.txt' to the specified directory. If you use 'mv file1.txt file2.txt', it effectively renames 'file1.txt' to 'file2.txt'.

Unlike a copy function, which creates a duplicate of the file in a new location, the 'mv' command removes the original file once it has been moved or renamed, ensuring that only one instance of the file exists in the system at any given time. This makes it efficient for managing file organization and structure within a Linux system.

The other options do not accurately describe the behavior of the 'mv' command. While copying files is a function of the 'cp' command, displaying contents refers to the 'cat' command, and the renaming function is just a subset of what 'mv' can accomplish, not its sole purpose. Thus, option B encapsulates the full capabilities of the 'mv' command.