Hello hellasphotography it does the job it says.
I always recommend any user to test what ever plugin they are installing to make sure that it is doing what it suppose to do. In this case you are installing a cache plugin. You should run some performance test on your website of blog.
One great site to use is gtmetix.com. Of course there are many more sites you can use to test the performance. Simply google it and you will see how many come up.
I hope this helps you test your site to see if it has improved or not.
Kind regards