Killing creeps to earn gold in Dota 2 is commonly called farming. Farming is the process of gathering reliable resources from lane creeps, neutral creeps, and sometimes other map units so a hero can buy items and gain experience.
In lane, farming usually depends on last-hitting: delivering the final attack that kills a creep. The hero who gets the last hit receives the creep's gold, while nearby allied heroes may still receive experience. This makes timing and positioning especially important, because missed last hits reduce a player's income.
The term is broader than last-hitting alone. A carry may farm a lane, a support may farm a neutral camp when safe, and a team may use smoke, wards, or rotations to protect a farming hero. Pulling and stacking are techniques that can improve farming efficiency, not synonyms for it.
Farming is central to Dota 2's economy, but it carries risk: a hero spending too long collecting gold can leave teammates outnumbered or become vulnerable to an enemy gank.