While a revolution can include a coup d’état, not all coups d’état actually result in revolution. That is because a revolution must include a fundamental change in a society.
For example, the French Revolution and the Haitian Revolution were undeniably revolutions rather than mere coups. The French Revolution took power from the aristocracy and monarchy and gave it to the Third Estate. It made the society more democratic. In Haiti, the Revolution abolished slavery and destroyed the system of white supremacy and white rule in Haiti. These were true and fundamental changes and are therefore called revolutions.
However, other changes in government can simply be done because one faction in the elite of a society wants more power. This faction does not really want to change society in any real way. Instead, it simply wants to have power so that it can gain the benefits that come with having power. This often happens in “Third World” countries where, for example, one military strong man overthrows another. Such a coup leads to no fundamental change even though it replaces one government with another.