Literally a servant. An office of servant ministry within the church. "But let these also first be proved; then let  them serve as deacons, being found blameless" (1 Tim. 3:10).

Disciple is one who is taught or trained.   "And whoever does not bear his cross and come after Me cannot be My disciple" (Luke 14:27).

Discipleship is being called to walk with Christ, equipped to love like Christ and sent by Christ to love and serve others in the world!