Thanks for your question, Phoebe.
Only the elected members of the House of Representatives are allowed to make decisions on proposed laws and other issues by voting ‘on the voices’ or taking part in a division—a formal vote of Parliament.
The Clerk and Serjeant-at-Arms are non-elected employees who work for the Parliament. They belong to the Australian Parliamentary Service.
Like all parliamentary staff, the Clerk and Serjeant-at-Arms had to apply for their position and be successful at a job interview. They will usually have worked in other positions at Parliament House and have a lot of experience with how the Parliament works.