Aerial interdiction is a specific type of ground attack mission carried out by military aircraft. Interdiction refers to attacks made behind enemy lines targeting the infrastructure used by the enemy to store and move troops and materiel to the front lines. This can include roads, bridges, troop transports and cargo aircraft, fuel depots, and ammunition storehouses.
Interdiction is distinguished from close air support, which deals with the direct attack of enemy ground forces on the battlefield, usually in support of friendly troops. Offensive counter air missions, including attacks on enemy runways, can be considered a type of interdiction mission, but OCA operations have become a more specialized field, owing the unique complexities of targeting enemy aircraft and runaways.
Many fighter bombers were also designed to engage in aerial combat immediately after attacking ground targets.
Perhaps the one meaningful distinction at present is the question of range: a bomber is generally a long-range aircraft capable of striking targets deep within enemy territory, whereas fighter bombers and attack aircraft are limited to 'theater' missions in and around the immediate area of battlefield combat.
Even that distinction is muddied by the availability of aerial refueling, which greatly increases the potential radius of combat operations.