diff --git a/sound.md b/waves-characteristics.md
similarity index 85%
rename from sound.md
rename to waves-characteristics.md
index 4434d2f..dae368b 100644
--- a/sound.md
+++ b/waves-characteristics.md
@@ -12,6 +12,10 @@ The movement of the disturbance through a medium due to repeated periodic motion
      Mechanical Wave - *Periodic* disturbance which *requires material medium* (i.e. solid, liquid or gas) *for its propagation*.
      These waves are characterized by the motion of the particles of a medium.
      These waves have well defined characteristics.
+<blockquote>
+If the particles of a medium oscillate to and fro in the direction of wave propagation -> longitudinal wave
+If the particles of a medium oscillate to and fro perpendicular to the direction of wave propagation -> Transverse wave
+</blockquote>
      </td>
      <td>
      ii. Electromagnetic Wave