Understanding the fundamental differences between these two styles of play will help you find the right game for your taste.

Both genres share a common ancestry, tracing their roots back to custom map modifications in classic RTS titles.
The Classic Tower Defense
The player's sole objective is to build static structures along a predetermined path to stop incoming waves of enemies.

It is a test of endurance, mathematical optimization, and predicting AI movement patterns over long play sessions.
Almost always single-player.You wait for the enemies to come to you.Pacing is generally slow and methodical. The Modern Tower Rush
You are actively deploying mobile troops that march down lanes while also managing your own defensive structures.

This genre requires lightning-fast reflexes, quick economic calculations, and the ability to read your opponent's mind.
FeatureClassic TDTower RushWinning ConditionSurvive all waves without losing livesTake more towers than the opponentPlayer ActionManaging trapsCountering enemy pushes Finding Your Preference
Both genres offer incredible depth and satisfaction, but they cater to very different psychological needs.

The evolution from static defense to dynamic rushing proves that strategy games are constantly reinventing themselves.