An airplane can be a Monoplane or Biplane.
An airplane with one pair of wings is a monoplane.
Monoplane
monoplane
It was a Ryan Monoplane.
An airplane with a single pair of wings is called a "monoplane." This is opposed to a "biplane" which has two pairs of wings or a "triplane" which has three. Since biplanes and triplanes have become so rare, the phrase "monoplane" has fallen into disuse as the monoplane configuration is regarded as being the standard.
That is a monoplane. The one in the picture above is a biplane.
A Monoplane is a airplane with one main wing. This has been the dominate design for planes since the 1930's.
The first successful French airplane, a tractor monoplane named the "Blériot VII," was introduced in 1907 by Louis Blériot.
Monoplane
The US organized their early air force as a part of the US Army. Their aircraft was identified as by the type and model number. One type of airplane was a Pursuit plane and they were identified by "P" such as the P-40.A monoplane is an airplane with a single wing as compared to a Biplane. The very first fighters were biplanes in WW1 and soon after that. So the first single wing figher planes could be referred to as "pursuit monoplane". One of the first US monoplane fighters was the P-26 Pea Shooter.
Aircraft with one set of wings i.e 737-800
A monoplane is a planes with just an engine.