According to the Synoptic Gospels, Jesus appointed twelve apostles.
Mark, Matthew, and Luke each present a group of twelve specially chosen followers. The number reflects the twelve tribes of Israel and gives the group symbolic importance within Jesus’ mission. The apostles are named in lists, although the order and some wording vary between the Gospels.
The Twelve were not the only people who followed Jesus. The Gospel narratives also describe larger circles of disciples, including the seventy or seventy-two sent out in Luke. “Disciple” is a broader term for a learner or follower, while “the Twelve” identifies the central appointed group.
After Judas Iscariot’s death, Acts describes the apostles choosing Matthias to restore the number to twelve. Paul is also called an apostle in the New Testament, but he was not one of the original Twelve selected during Jesus’ ministry.