Earth's tectonic plates are constantly moving and shifting, and the boundaries between these plates are where much of the world's seismic activity, including earthquakes, occurs. The boundaries between tectonic plates can be classified into three types: divergent, convergent, and transform.
At divergent boundaries, tectonic plates are moving away from each other, and earthquakes in these areas are generally less intense. However, these boundaries are often associated with the formation of new oceanic crust, and can be the site of volcanic eruptions.
At convergent boundaries, tectonic plates are moving towards each other, and earthquakes in these areas can be very intense. These boundaries are often associated with the collision and subduction of tectonic plates, and can be the site of earthquakes, volcanic eruptions, and mountain building.
At transform boundaries, tectonic plates are sliding past each other, and earthquakes in these areas can be of moderate intensity. These boundaries are often associated with the creation of strike-slip faults, such as the San Andreas Fault in California.
Overall, the location of most earthquakes is concentrated along the boundaries between tectonic plates, particularly at convergent and transform boundaries.