The three sub reports that you see are:
Network Location: This will tell you about where the network that the user is connected to is. This is what provides you with information about the ISP that the Web user is connecting to the Internet with. While this is not too relevant, it helps solidify the location of your audience. Though speaking from personal experience, I have seen my network location show up in an area about 60 miles from my actual location. Google Analytics will be more reliable than the Analytics that brought this result. Yet, you should consider this when it comes to the accuracy of the information.
Hostnames: This is merely a phrase for the domain name. It helps to see whether or not you have several domains pointing to the same Web site. So, you can see where most of your traffic is coming from in terms of advertising. Certain domains will work better than others depending on various factors. So, if you are using more than one domain name, you should take heed to which ones are effective and consider ditching the others.
Connection Speeds: This is likely the most useful of all three sub-reports because it will tell you about the speed of the connection the user has, which means you will be able to tell more about how long it takes a page to view. It will also tell you whether or not they would be able to handle large file downloads in a timeframe that is short enough to remain user friendly. Web browsers are typically impatient so you should not keep them waiting with downloads when you do not need to.