Mark is a Roman name, and his other name, John, is Hebrew and means the LORD is gracious.
About
John, also called Mark, not the apostle John. Many gathered to pray at the house of his mother Mary in Jerusalem, and Peter came there after the Lord delivered him from Herod. Barnabas and Saul took Mark with them, and he served as their helper on Cyprus. At Perga he left them and returned to Jerusalem, and Acts does not say why. Paul later refused to take him, and Barnabas, Mark's kinsman, sailed with him to Cyprus. Paul's later letters name him as a useful fellow worker, and Peter called him his son. The second Gospel names no author, and the church has ascribed it to Mark since early times.
Relationships
RelativeBarnabasKinsman, his cousin or his mother's brother, who took him to Cyprus
Co-workerPaulApostle who refused to take him again and later called him useful
CompanionPeterApostle who came to his mother's house and called him his son
Key Scripture AppearancesKJV
Acts 12:12
And when he had considered the thing, he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying.Acts 12:12, KJV
Acts 13:13
Now when Paul and his company loosed from Paphos, they came to Perga in Pamphylia: and John departing from them returned to Jerusalem.Acts 13:13, KJV
Acts 15:39
And the contention was so sharp between them, that they departed asunder one from the other: and so Barnabas took Mark, and sailed unto Cyprus;Acts 15:39, KJV
2 Timothy 4:11
Only Luke is with me. Take Mark, and bring him with thee: for he is profitable to me for the ministry.2 Timothy 4:11, KJV
1 Peter 5:13
The church that is at Babylon, elected together with you, saluteth you; and so doth Marcus my son.1 Peter 5:13, KJV
See how Mark connects to every other figure in Scripture.