challenges

As nouns the difference between taxonomy and challenges

is that taxonomy is the science or the technique used to make a classification while challenges is plural of lang=en.

As a verb challenges is

third-person singular of challenge.

As a verb challenges

is .

As a noun mechanism is

within a machine or machinery; any mechanical means for the conversion or control of motion, or the transmission or control of power.

As a verb challenges

is .

As a noun problem is

problem.