In Christianity, the term disciple primarily refers to students of Jesus and is found in the New Testament only in the Gospels and Acts. The New Testament records many followers of Jesus during his ministry, but only some became disciples. Some disciples were given a mission, such as the Little Commission, the commission of the 70 in Luke's gospel, the Great Commission after the resurrection of Jesus, or the conversion of Paul, making them Apostles, charged with proclaiming the gospel (the Good News) to the world. Jesus emphasised that being his disciples would be costly.
The term "disciple" is derived from the Koine Greek word mathetes, which means a pupil (of a teacher) or an apprentice (to a master craftsman), coming to English by way of the Latin discipulus meaning a learner while the more common English word is student. A disciple is different from an apostle, which instead means a messenger. While a disciple is one who learns from a teacher, an apostle is one sent to deliver those teachings.
In addition to the Twelve Apostles there is a much larger group of people identified as disciples in the opening of the passage of the Sermon on the Plain. In addition, seventy (or seventy-two, depending on the source used) people are sent out in pairs to prepare the way for Jesus (Luke 10). They are sometimes referred to as the "Seventy" or the "Seventy Disciples". They are to eat any food offered, heal the sick and spread the word that the Kingdom of God is coming.