I haven't used this so I can't tell if it any good, but I can tell you what it does.
Apache uses a file called httpd.conf which contains all of the information Apache needs to start up and run. If you know what to type in, you can modify the httpd.conf file by hand - but that can be a bit tricky if you don't understand all of the things that can go into the file.
Apache by itself does not have a GUI based config tool. There are a few out there, but I have not found any I really like.
One of the things you can do with Apache is set up directories so that the user needs a user ID and password to get access. According to the description, this package gives you a GUI tool to configure the directories you want to protect and set up the required User IDs.
Regarding networking between Macs and PCs, if you have files on your Mac that you want to be able to download to a PC and you want to protect those files by User ID, you could use this package to configure that, then download to the PC using a browser.