In addition to the explanation others have mentioned, here it is in graph form. See the where the graph of 2^x intersects the y axis (when x=0):
https://people.richland.edu/james/lecture/m116/logs/exponential.html
This also has some additional verbal explanations:
http://scienceline.ucsb.edu/getkey.php?key=2626
The simplest way I think of it is by the properties of exponentials:
2^3 / 2^2 = (2 * 2 * 2) / (2 * 2) = 2 = 2^(3-2)
Dividing two exponentials with the same base (in this case 2) is the same as that same base (2) to the power of the difference between the exponent in the numerator minus the exponent in the denominator (3 and 2 in this case).
Now lets make both exponents the same:
2^3 / 2^3 = 8/8 = 1
2^3 / 2^3 = 2^(3-3) = 2^0 = 1
Do a search for you server OS + STIG
Then, for each service you’re hosting on that server, do a search for:
Service/Program name + STIG/Benchmark
There’s tons of work already done by the vendors in conjunction with the DoD (and CIS) to create lists of potential vulnerable settings that can be corrected before deploying the server.
Along with this, you can usually find scripts and/or Ansible playbooks that will do most of the hardening for you. Though it’s a good Idea to understand what you do and do not need done.