Military intelligence is a military discipline that uses information collection and analysis approaches to provide guidance and direction to assist commanders in their decisions. This aim is achieved by providing an assessment of data from a range of sources, directed towards the commanders' mission requirements or responding to questions as part of operational or campaign planning. To provide an analysis, the commander's information requirements are first identified, which are then incorporated into intelligence collection, analysis, and dissemination.

Areas of study may include the operational environment, hostile, friendly and neutral forces, the civilian population in an area of combat operations, and other broader areas of interest. Intelligence activities are conducted at all levels, from tactical to strategic, in peacetime, the period of transition to war, and during a war itself.

Most governments maintain a military intelligence capability to provide analytical and information collection personnel in both specialist units and from other arms and services. The military and civilian intelligence capabilities collaborate to inform the spectrum of political and military activities.

Personnel performing intelligence duties may be selected for their analytical abilities and personal intelligence before receiving formal training.

Intelligence operations are carried out throughout the hierarchy of political and military activity.

Strategic intelligence is concerned with broad issues such as economics, political assessments, military capabilities and intentions of foreign nations (and, increasingly, non-state actors). Such intelligence may be scientific, technical, tactical, diplomatic or sociological, but these changes are analyzed in combination with known facts about the area in question, such as geography, demographics and industrial capacities.

Strategic Intelligence is formally defined as "intelligence required for the formation of policy and military plans at national and international levels", and corresponds to the Strategic Level of Warfare, which is formally defined as "the level of warfare at which a nation, often as a member of a group of nations, determines national or multinational (alliance or coalition) strategic security objectives and guidance, then develops and uses national resources to achieve those objectives."

Operational intelligence is focused on support or denial of intelligence at operational tiers. The operational tier is below the strategic level of leadership and refers to the design of practical manifestation. Formally defined as "Intelligence that is required for planning and conducting campaigns and major operations to accomplish strategic objectives within theaters or operational areas." It aligns with the Operational Level of Warfare, defined as "The level of warfare at which campaigns and major operations are planned, conducted, and sustained to achieve strategic objectives within theaters or other operational areas."