Under Linux, all data are stored as les. Most users are familiar with the two primary types of les:
text and binary. But the /proc/ directory contains another type of le called a virtual le. It is for this reason that /proc/ is often referred to as a virtual le system.
These virtual les have unique qualities. Most of them are listed as zero bytes in size and yet when one is viewed, it can contain a large amount of information. In addition, most of the time and date settings on virtual les reect the current time and date, indicative of the fact they constantly changing.
Virtual les such as interrupts, /proc/meminfo, /proc/mounts, and /proc/partitions provide an up-to-the-moment glimpse of the system's hardware. Others, like /proc/filesystems and the /proc/sys/ directory provide system conguration information and interfaces.
For organizational purposes, les containing information on a similar topic are grouped into virtual directories and sub-directories. For instance, /proc/ide/ contains information for all physical IDE devices. Likewise, process directories contain information about each running process on the system.
