DISCIPLE and APOSTLE, what is the difference?

DISCIPLE (Greek "mathetes", "a learner"), the word appears in the Greek Scriptures referring to the disciples of Jesus, of John the Baptist, of the Pharisees, and of Moses. (Matt. 9:14; Luke 5:33; John 9:28; Mark 2:18). The context in which the word is mention give us the idea of a follower, pupil, or adherent of a teacher or religious leader. Jewish and Greco-Roman history and literature provide also examples of respected figures who gather disciples in order to teach and lead them.
A general distinction between Jesus' disciples and "the crowds" have to be observed according to their commitment to the leader. The disciples were committed followers while "the crowds" were just onlookers not seriously attached to him. Yet even some of those in the larger group of "disciples" turned away from Jesus and went back to their former lives when they found his teaching difficult to accept (John 6:60, 66).
The principal application of the Gospel to the definition of disciples of Jesus usually applies to the body of intimate followers who travelled with him on his preaching tours and who were taught and instructed by him. The effectiveness of Jesus' teachings continue through the work his disciples do to this very day. They are not making disciples for themselves for it is the teaching not of men, but of Christ, that the people of the world follow.
Jesus' first disciples came from among the disciples of John (John 1: 35-42). The Twelve chosen as apostles are called disciples at Matthew 10: 1 and 11: 1.
APOSTLE (Greek "apostolos", "one sent forth to represent the sender"). This word derives from the common Greek verb "apostellein," meaning simply "to send forth or off." Its basic sense is clearly illustrated in Jesus' statement : "A slave is not greater than his master, nor is one that is sent forth (apostolos) greater than the one that sent him." (John 13 : 16). In these sense the word also applies to Christ Jesus as the "apostle and High Priest whom we confess." (Hebrew 3:1; compare Matthew 10:40; 15:24; Luke 4:18, 43; 9:48; 10:16; John 3:17; 5:36, 38; 6:29, 57; 7:29; 8:42; 10:36; 11:42; 17:3, 8, 18, 21-25; 20:21). Jesus was sent forth by God as his special appointed and commissioned apostle, a special messenger from God (2 Kings 2:2; 2 Samuel 24:13).
According to Mark 3: 14-15  JESUS' appointed Twelve, whom he also named apostles, to BE with HIM, and to BE SENT OUT to proclaim the message, and to have AUTHORITY to CAST OUT DEMONS" (Matt.10: 1-4; Luke 6: 13-16).
Initially, Jesus sent the Twelve "to the lost sheep of the House of Israel," rather than to the Gentiles or the Samaritans (Matt. 10: 5-6; 15:24). The relevance of the Twelve to the House of Israel becomes explicit in Matt. 19:28, where Jesus remark to his disciples: "Truly I tell you, at the renewal of all things, when the Son of Man is seated on the throne of his glory, you (the apostles) who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel." The Twelve thus represent Jesus' mission to bring renewal to all the House of Israel, through his inauguration of the kingdom of God.
(Rev. 21: 12-14).
The New Testament does not restrict the term "apostle" to the ones selected by Jesus in the beginning of his ministry. Instead the title is being applied to the ones divinely selected and commissioned to continue to the apostolic work in the name of Jesus. To fortified the strength of their testimony they continue to exercise the miraculous powers previously granted to the first ones by Jesus and also other gifts of the Spirit mentioned being received  from Pentecost forward. (Acts 5;12; 9: 36-40). While other disciples, too, received such miraculous gifts of the Spirit, the accounts shows that such was the case only when one or more of the apostles were present, or by the laying on of the hands of the apostles. Thus the power of transmittal as regards these gifts was unique with the apostles as long as the apostolic strength of their testimony was present and able to be exercised (Acts 2:1, 4, 14; 8: 14-18; 10:44; 19:6).
Paul implies that James, the brother of Jesus, was an apostle (1 Cor. 9:5), and in 1 Corinthians 15:9 Paul refers to himself as an apostle (1 Cor. 9:1; 2 Cor. 11:5; Gal.1:1). In Acts 14:14 Luke refers to Barnabas and Paul as apostles, and in Rome 16:7 Paul implies that Adronicus and Junias were apostles at Rome.
Paul, also, distinguished TRUE from FALSE apostles (2 Cor. 11:13; Rev. 2:2), and he acknowledged "signs of a true apostle," including "signs and wonders and mighty works" (2 Cor. 12:12).