can anyone tell what it is,i hear it a lot but don't know what to look for

Rip Rap is the rock placed down levees, dams, roadbeds etc.

Its rocks piled along the bank. Like what you would see along a levee or a dam.

rip·rap  (r[ch301]p'r[ch257]p')   

n. 

A loose assemblage of broken stones erected in water or on soft ground as a foundation.

The broken stones used for such a foundation.

tr.v.   rip·rapped, rip·rap·ping, rip·raps

To construct a riprap in or on.

To strengthen with a riprap.