Okay, I have noticed a flaw in dedicated server industry and it is with the advertising of managed vs unmanaged services.
It varies greatly and it doesn't mean the same thing uniformly much to my disappointment. However, it is due to customer demand.
Firstly, some people say managed is looking after the server, DNS, control panel etc and you just host off it.
If you are getting a dedicated server the least people could do is read up on this stuff. You need to have basic skills to administer the server. Learn about DNS, MX Records, Mail servers, Operating Systems etc. http://www.wikipedia.com/
Now, to some people this is managed, to some people you have the skill. Where did it evolve from? This perception of managed evolved from clients with shared webhosting who simply outgrew their service, however didn't have the expertise to manage a machine. After all, they probably didn't even build the webserver themselves, nor the website. They just used the computer/internet as a tool for their business without using it directly, but through a 3rd party.
Now the other perception of managed comes from the intermediate users to professionals. As you realise security is a huge risk, especially these days with DDos attacks becoming more and more common and random, it is important to maintain the integrity of our data. We can do this in several ways.
Making sure the server is safe software wise, and physically hardware wise.
So software wise, managed services included extra support such as phone/tech 24/7, fixing security holes in known software, updating software etc. On the hardware side it's the constant upgrading and maintenance of the hardware you pay for. Sometimes it includes the addition of physical firewalls / rebooting ports.
So really the definition of managed changes depending on the context it's used in and it's due to customer demand.
In the end, no matter if they say managed or un-managed, always look to see what they REALLY do. Your understanding of managed can be completely different to others, it is something that really isn't clear cut.
Hopefully this clears a few things up for people.
There is no uniform meaning for "managed" in this industry.