The Gospels are Matthew, Mark, Luke, and John. Essentially, they are biographies.
Three of them: Matthew, Mark, and Luke are called the synoptic – from the word synoptic, which means a summary view – gospels, because they tell the same events from Jesus’s life.
The Gospel of John deals with matters not found in the synoptic gospels.
Matthews Gospel is written primarily to the Hebrews. It deals with Old Testament, and how Jesus fulfilled the requirements of the Messiah.
The Gospel of Luke was written to convince Gentiles. It was written in vernacular Greek, and assumes the the reader would not be familiar with Jewish law.