Final answer:
The 'lsof' command in Linux is a multifunction tool for listing open files and is critical for tasks related to troubleshooting and system monitoring.
Step-by-step explanation:
In Linux command-line tools, lsof is a multifunction tool for listing open files. This command provides a wealth of information including which files are opened by which process. By using lsof, you can see the list of files that are currently opened, which is particularly useful for troubleshooting and system monitoring.
For example, you can use this tool to determine which process is using a particular file, or to see which files are being accessed by a network service. The lsof command is very powerful and provides more than 100 different pieces of information about open files. It is typically used by system administrators and is an important part of a Linux user's toolkit, especially when they need to deal with file and process management.