First of all lets see the structure of SAP Commerce Cloud version 1905.
Go inside bin directory.
here we can see 2 sub directories:
Lets move inside modules directory.
It contains all the modules and extensions ,which is out of the box in Commerce Cloud.
Note : In old versions like 5.x and 6.x had all the modules and extensions along with platform. But now these extensions and modules are moved into modules directory.
Also check the platform and then open command prompt from here.