The gospels of Matthew, Mark, and Luke are referred to specifically as the Synoptic Gospels because they include many of the same stories, often in the same sequence, and similar wording that cannot be accounted for by the Christian Oral Tradition. This degree of parallelism in content, narrative arrangement, language, and sentence structures can only be accounted for by literary interdependence. Many scholars believe that these gospels share the same point of view and are clearly linked. The term synoptic comes from the Greek syn, meaning "together", and optic, meaning "seen".
According to the majority viewpoint, Mark was the first gospel written. Matthew and Luke then used Mark as a source, as well as a hypothetical sayings gospel known as Q. Matthew and Luke also included unique material, and the sources for this material are designated M and L, respectively.
The Synoptic Gospels are the primary source for historical information about Jesus.
Apocryphal gospels, as well as the canonical Gospel of John, differ greatly from the Synoptic Gospels.
Read more about Synoptic Gospels: Structure, The Problems With Q