Civil service is a term that is meant to refer to the branches of employment that are directly tied to the government in some form. Civil service will include any profession that is part of some governmental agency, with the only exception being the military.
Generally speaking, civil service jobs are considered to be very competitive, and people are hired and employed based on professional merit. Any person that is considered to be in the civil service will often times be referred to as a civil servant or public servant.
A civil servant will also include any person that is employed by the federal, state, and local governments, though the definition of the term will vary from country to country. However, the civil servant employee body is what makes up the civil service of a country. Civil service will essentially include of the divisions or departments that make up the government of a nation.
Typically speaking, a civil service job will be independently responsible for aspect such as the hiring process, defining and distributing raises, and establishing employee benefits. Furthermore, civil service branches will also be responsible for any testing and examinations that are administered.
As mentioned, most civil service jobs or careers are highly competitive, and thus, hire only the best qualified applicants. However, each branch of the civil service will have to abide by overarching national or federal standards and regulations.