Continental Staff System

A military staff (often referred to as general staff, army staff, navy staff, or air staff within the individual services) is a group of officers, enlisted and civilian personnel that are responsible for the administrative, operational and logistical needs of its unit. It provides bi-directional flow of information between a commanding officer and subordinate military units. A staff also provides an executive function where it filters information needed by the commander or shunts unnecessary information.

One of the key purposes of a military staff is to provide accurate, timely information (which includes the results of contingency planning) on which command decisions are based. A goal is being able to suggest approaches or help produce well-informed decisions that will effectively manage and conserve unit resources.

In addition to generating information, the staff also manages the flow of communication within the unit and around it. While controlled information flow toward the commander is a priority, those useful or contingent in nature are communicated to lower-level units and/or through their respective staffs. If the information is not pertinent to the unit, it is redirected to the command level which can best utilize the condition or information.

Staffs are generally the first to know of issues that affect its group. Issues that require major decisions affecting the unit's operational capability are communicated to the commanding officer. However, not all issues will be handled by the commander. Smaller matters that arise are given to a more appropriate tasker within the unit to be handled and resolved, which would otherwise be an unnecessary distraction for the Commanding Officer who already makes numerous decisions every day.

In addition, a staff aims to carefully craft any useful situations and utilize that information.

In a generic command staff, more seasoned and senior officers oversee staff sections of groups organized by the needs of the unit. Senior Enlisted Personnel task personnel in the maintenance of tactical equipment and vehicles. Senior Analysts are tasked with the finalizing of reports, and their enlisted personnel participate in the acquisition of information from subordinate staffs and units. This hierarchy places decision making and reporting under the auspices of the most experienced personnel and maximizes information flow of pertinent information sent out of the command overall, clarifying matters overall. This frees up the most senior members of the command at each level for decision making and issuing direction for further research or information gathering (perhaps requiring men to put their lives at risk to gather additional intelligence).

...
Wikipedia