So, map awareness and Target priority.
Map Awareness
Definition : Knowing where every thing is on the map, the term usually concerns enemies, but allies are important in low communication environment (i.e: Low com pubs, and random team tournaments )
It also includes knowing the countdown, Movement speed, armor, Magic resistance, HP/MP(Very important), HP/MP regen, items of each hero and Roshan status ( As always, if you're in high communication environment you can ignore allies to some extent ).
Important points :
Minimap : Very important, it gives knowledge over Positions, and vague Movement speed.
Hero status : You should check their inventories for items, and for big ultimates/spells heroes, you should keep counting their ults/spells. As you can't get vision over the entire map ( usually ) you should expect the enemy heroes positions, activites and items as the game goes along.
Wards : They need to see the heroes, give information of items, positions and activity of enemy heroes and units, works in harmony with Minimap.
Roshan : Keep vision around Roshan and know if they're in the pit, without forgetting about the Roshan respawn time (8-11 minutes)
Heroes that use it extensively : Invoker, Bloodseeker, AA, Skill shot heroes, Supports, Roamers and Gankers.
Target Priotity
Definition : It's the act of prioritizing a enemy hero/unit in a teamfight to drop him dowm quickly.
Important Points :