Question

What is the similarity between trenches and subduction zones?

Answer 1

I'll give you an example.

If two tectonic plates clide, more or less in a head-on collision, they form a convergent plate boundary.
Usually, one of the converging plates will move beneath the other, which is known as
subduction.
Deep trenches are often formed where tectonic plates are being subducted, and earthquakes are common.