When documenting your network infrastructure, you are obtaining both hardware data to document your infrastructure's physical structure and software data to document the existence and configuration of the protocols in use on your network.
1. perpendicular-a straight line at right angles to another line. straight line-a line traced by a point traveling in a constant direction; a line of zero curvature; the shortest distance between two points is a straight line.
Skew lines are lines that are in different planes, are not parallel, and do not intersect. Parallel lines, as you will recall, are lines that are in the same plane and do not intersect. Also, remember that in mathematics, lines extend forever in both directions.