The competitive service is a part of the United States federal government

Federal government of the United States

The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...

 civil service

Civil service

The term civil service has two distinct meanings:* A branch of governmental service in which individuals are employed on the basis of professional merit as proven by competitive examinations....

. Applicants for jobs in the competitive civil service must compete with other applicants in open competition under the merit system administered by the Office of Personnel Management

Office of Personnel Management

The United States Office of Personnel Management is an independent agency of the United States government that manages the civil service of the federal government. The current Director is John Berry.-History:...

.

According to U.S. Code

United States Code

The Code of Laws of the United States of America is a compilation and codification of the general and permanent federal laws of the United States...

 Title 5

Title 5 of the United States Code

Title 5 of the United States Code outlines the role of government organization and employees in the United States Code. It also is the Title that specifies Federal holidays .* Part I: The Agencies Generally...

 §2102,
The "competitive service" consists of—

1. all civil service
   Civil service
   The term civil service has two distinct meanings:* A branch of governmental service in which individuals are employed on the basis of professional merit as proven by competitive examinations....
   
    positions in the executive branch, except—
   1. positions which are specifically excepted
      Excepted service
      Most civilian positions in the federal government of the United States are part of the competitive service, where applicants must compete with other applicants in open competition under the merit system administered by the Office of Personnel Management. However, some agencies are excluded from...
      
       from the competitive service by or under statute
      Statute
      A statute is a formal written enactment of a legislative authority that governs a state, city, or county. Typically, statutes command or prohibit something, or declare policy. The word is often used to distinguish law made by legislative bodies from case law, decided by courts, and regulations...
      
      ;
   2. positions to which appointments are made by nomination
      Nomination
      Nomination is part of the process of selecting a candidate for either election to an office, or the bestowing of an honor or award.In the context of elections for public office, a candidate who has been selected by a political party is normally said to be the nominee of that party...
      
       for confirmation by the United States Senate
      United States Senate
      The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
      
      , unless the Senate otherwise directs; and
   3. positions in the Senior Executive Service
      Senior Executive Service
      The Senior Executive Service is a paygrade in the civil service of the United States federal government, somewhat analogous to the ranks of general or admiral in the U.S. armed forces...
      
      ;

Notably, the procedures for firing and demoting a member of the competitive service are considerable in order to protect the employment rights of the member, yet to provide the employer (the US government) a fair and incremental method to manage employees. A written notice of thirty days, a statement of reasons for dismissal, and a right to a hearing must be granted.