# What is symmetric?

What is symmetric?Please explain geometrically and in terms of displacements. I have encountered this while looking up for engineering strain and true strain values have totally different compression and expansion parameters for their respective strains.

Note, this does not mean that compressive and tensile value must be the same. It basically means that if you have for material sample, you will measure the same properties, whether you measure them in $x$, $y$ or $z$ direction.