It is called a Kepi.
Beret
A flat army cap is commonly referred to as a "garrison cap" or "flight cap." It is a type of military headgear that is characterized by its flat, foldable design and is often worn by military personnel. In some contexts, it may also be called a "service cap" or "barracks cap."
A kepi is a French military cap.
There are loads of different types of military hats. For example, you could have a beret, a chauffeur military cap, a patrol field cap, or a regular baseball cap.
A peaked cap is commonly referred to as a "visor cap" or "military cap." Another popular name for it is "golf cap," especially when associated with leisure activities. In some contexts, it may also be called a "newsboy cap" or "flat cap," although these terms can refer to slightly different styles.
A cadet's hat is commonly referred to as a "barracks cap" or "garrison cap." It is a type of military headgear typically worn by cadets and service members, characterized by its folded design and lack of a visor. In some military academies, it may also be called a "cover." The style and insignia can vary based on the specific branch of the military or organization.
A clergyman's cap is called a biretta.
Veterans do not wear uniforms, except that some who are members of veterans' organizations at times wear a military-style cap (called a garrison cap) with ribbons and buttons representing their organizations.
A tasselled cap is called a Fez.
The name given to a military cap with a circular top and a horizontal peak is a "beret."
A Red Cap is a nick name given to Military Police
It can be called a cap or a scarf.