You will be given a definition of a task first, then some input of the task.
In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Seismic waves are divided into two main types of waves , body waves and surface waves .
Output:
Among the many types of seismic waves , one can make a broad distinction between " body waves " , which travel through the Earth , and " surface waves " , which travel at the Earth 's surface .