Introduction:
In ancient times, people did not have the scientific knowledge and tools to understand the true causes of earthquakes. Their understanding of natural phenomena was limited, and they often attributed earthquakes to supernatural or divine causes. However, over time, scientific advancements and research have led to a better understanding of the true causes of earthquakes.

Explanation:
Ancient people's understanding:
- In ancient times, people believed that earthquakes were caused by the anger of gods or the actions of mythical creatures.
- Many ancient civilizations, such as the Greeks and Romans, believed that earthquakes were the result of the movements of gods or giants beneath the Earth's surface.
- They associated earthquakes with the wrath of gods or as signs of impending doom or divine intervention.

Lack of scientific knowledge:
- The lack of scientific knowledge and tools in ancient times prevented people from accurately understanding the causes of earthquakes.
- They did not have the means to measure or study seismic waves, fault lines, or tectonic plates, which are crucial in understanding the true causes of earthquakes.
- Without this knowledge, they relied on myths, legends, and religious beliefs to explain the occurrence of earthquakes.

Scientific advancements:
- In modern times, scientists have made significant advancements in the field of seismology, which is the study of earthquakes and seismic waves.
- Through the use of seismographs, scientists can measure and record the intensity, duration, and location of earthquakes.
- They have discovered that earthquakes are primarily caused by the movement of tectonic plates, which are large sections of the Earth's crust that float on the semi-fluid mantle beneath.
- The Earth's crust is divided into several tectonic plates, and when these plates interact, they can create stress and pressure that eventually leads to earthquakes.

Plate tectonics:
- Plate tectonics theory explains that the Earth's crust is divided into several large and small plates that continuously move and interact with each other.
- The boundaries between these plates are known as fault lines, and earthquakes commonly occur along these fault lines.
- The most common types of fault lines are transform boundaries, convergent boundaries, and divergent boundaries, each associated with different types of earthquakes.

Conclusion:
In ancient times, people did not possess the scientific knowledge and tools to understand the true causes of earthquakes. They attributed these natural disasters to supernatural or divine causes. However, with the advancements in seismology and the study of plate tectonics, scientists have been able to provide a more accurate understanding of the causes of earthquakes.