Footprinting is the first and most convenient way that hackers use to gather information about the environment of the target and architecture, usually for the purpose of finding ways to break into that environment. Footprinting can expose system flaws and identify the ease with which they can be exploited.
This is the simplest way for hackers to collect information about operating systems and the companies they belong to. The objective of this preparatory phase is to learn as much as you can about a system, its remote access capabilities, its ports and services, and any specific aspects of its security.
Footprinting is the method of creating a plan or map of an organization’s network and systems. Information gathering is also known as footprinting an organization. Footprinting starts by defining the target system, application, or physical location of the target. Once this information is known, specific information about the organization is gathered using nonintrusive methods.
“For example, the organization’s own web page may provide a personnel directory or a list of employee bios, which may prove useful if the hacker needs to use a social engineering attack to reach the objective.”
Whenever footprinting a target, keep in mind that you could discover something that you aren’t supposed to see. If this occurs then you need to talk with the system administrators and let them know about the discovery. You could get into serious trouble if you misuse the information you discover.