In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

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 .
Seismic waves are divided into two main types of waves , body waves and surface waves .