Heya! When staff applications get accepted, the player does not instantly become a Helper/Mod. They undergo a training session, and once that session is complete they are promoted to Helper. Think of the Helper rank as being an intern for a job! After time and proving your abilities and comfort, you would receive a promotion! This is kind of the same thing! After the player is comfortable with their abilities and knowledge of the server, in a variety of number of months they can be promoted to Moderator!
To sum this all up, from the first promotion of becoming staff you would stay Helper rank until you feel comfortable taking the role of a Moderator :D
Hope this helps!
- ashley<3