Fleet Scouting and Hunting is the activity of providing intel on and catching targets for your fleet to kill. Generally this intel is relayed to the FC if it is important enough.
Interceptors are generally used for this purpose due to being nullified, cheap, fast to warp, and having a bonus to tackle modules. However HICs, T3Cs, Stealthbombers, Recon ships, and even T1 frigates are all often used as well depending on the fleet.
Horde Hunting 101 Video (Long)
Horde Intel 101 Video (Long but very good, ignore Horde specifics)
https://adashboard.info/intel a commonly used dscan pasting tool