DOTA 2 Basic Skill: Denying Creeps, Tower & Hero
Denying creeps is very useful in game because it prevent the enemy from getting gold and reduce the experience that enemy gain from that creep. Denying a creep is same as last hitting, but it require you to press attack move key (usually 'A') then select
If you successfully deny a creep, an exclamation mark will shown on the map in your name's colour.
For denying hero, such as like this one where Shadow Fiend was doomed while his HP is lowering till death. By denying hero, you can prevent the enemy from getting gold from that kill.
Same as denying creeps, you can also do the same to the heroes.
Screenshot of denied hero in Dota 2.
The same method can also be applied to the towers. Denying a tower only give 100 gold to the enemies. :)