How would you describe a Testbench in your own words?

A testbench is a main component for a design verification engineer and so as the design, In order to verify the design functionality we require with the testbench, which reflects the same as that of the real environment the design could face, when it is actually made available to the users. The testbench plays a vital role in design verification because if the bug isnt recognised before the post silicon validation, it is a huge loss for a company.