Propulsion is the push that sends a vehicle forward. A car, a ship, a plane, or a rocket moves because something is driving it on; that driving force is propulsion.

PropulsionPropulsion is the push指的是那股推力，that sends a vehicle forward讓交通工具往前進。A car, a ship, a plane, or a rocket moves車子、船、飛機、或火箭會動，because something is driving it on是因為有東西在推著它前進——that driving force is propulsion那股推動的力量就是propulsion。

Engineers talk about a propulsion system — the engine, the fuel, and the parts that make the push. A rocket’s propulsion comes from hot gas shooting out the back; a boat’s may come from a propeller in the water.

Engineers talk about工程師會講到 a propulsion system推進系統——the engine, the fuel, and the parts that make the push也就是引擎、燃料、還有負責產生推力的那些零件。A rocket's propulsion火箭的propulsion comes from hot gas shooting out the back來自後方噴出的高溫氣體；a boat's may come from船的可能來自 a propeller in the water水裡的螺旋槳。

The word is a little technical. In everyday talk people more often say “power” or “the engine.” You will meet it in science class, in space news, and in writing about cars and planes.

The word這個字 is a little technical有點專業、偏技術性。In everyday talk日常講話，people more often say大家比較常說 "power" or "the engine."「power」或「the engine」（動力、引擎）。You will meet it你會在 in science class, in space news, and in writing about cars and planes科學課、太空新聞、還有講車子飛機的文章裡遇到它。

Though actually, the old Latin verb behind it could mean “drive forward” and also “drive away.” In English today, propulsion is almost always the useful forward push, not shoving something aside.

Though actually不過其實，the old Latin verb behind it它背後那個古拉丁文動詞 could mean "drive forward"可以指「往前推」 and also "drive away."也可以指「推開、趕走」。In English today在今天的英文裡，propulsion is almost always幾乎都是指 the useful forward push那種有用的向前推力，not shoving something aside而不是把東西推開。