We can all use a little help sometimes. When using a computer, the problem is often a simple lapse of memory—you might have forgotten the name of a command, or the details of how to use an option to a command whose name you do remember. For situations like these, modern OSs provide help systems. In Linux, these take several forms. One of the oldest of these is the manual page system, often referred to as man pages, after the command you use to read them. A more modern system with similar goals is the info page system. Beyond these two formal documentation systems are additional sources of information, such as tutorials and other manuals provided with the OS, online documentation, and consultation with experts.