The 12 disciples of Jesus were Peter, Andrew, James, John, Philip, Bartholomew, Thomas, Matthew, James, Thaddeus, Simon and Judas. The 12 are known as disciples instead of apostles because they were still followers of Jesus while he was on earth.
The term "apostle" references someone who is sent out. Jesus's followers were not sent out until after his resurrection and ascension. At that point, the remaining disciples who were told to witness about Jesus were referred to as apostles. Even though Judas was listed as a disciple, he did not become an apostle as the others did. After his betrayal of Jesus, he committed suicide by hanging himself. He committed suicide before Jesus was executed. There is some dispute over what he did with the gold that he made for betraying Jesus. One book in the Bible claims that the money was used to buy a potter's field.
After the betrayal by Judas, he was replaced with Matthias. The disciples chosen by Jesus came from various walks of life, including tax collectors and fishermen. According to Matthew 10:1-4, Jesus gave the disciples the power to heal diseases and cast out unclean spirits. Jesus trained them while he was with them and helped them to understand what God wanted for mankind.