The wing root is the part of the wing on a fixed-wing aircraft that is closest to the fuselage

Fuselage

The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

. On a simple monoplane

Monoplane

A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

 configuration, this is usually easy to identify. On parasol wing

Parasol wing

A parasol wing monoplane is an aircraft design in which the wing is not mounted directly to the fuselage, but rather, the fuselage is supported beneath it by a set of struts, called cabane struts...

 or multiple boom aircraft, the wing may not have a clear root area.

Wing roots usually bear the highest bending forces in flight and during landing, and they often have fairings to reduce interference drag between the wing and the fuselage.

The opposite end of a wing from the wing root is the wing tip.