2 different bands? I'm unsure what you mean here. All the bands listed on that article are ham related - only those below 30 mhz are considered 'HF' or 'high frequency'.
In general any frequency above 2 mhz (most manuals will say 3 mhz) and 30 mhz is considered HF. There are radios that cover the entire HF spectrum, plus some of the other bands as well. It's all in the ham realm.
HF is a definition of a radio band, whereas, Ham is a nick name for the Amateur radio service.
HF is a definition of a radio band, a range of frequencies, from 3 MHz to 30 MHz, or also named by the wave length, from 100 meters to 10 meters.
Ham is a nick name for the Amateur radio service. The services are how portions of the radio bands, and/or specific frequencies are assigned and/or licensed to be used.
While there are a good number of ham frequency sub-bands in HF, there are also many outside of HF.
There are many other services within HF, such as Broadcast, Land and Marine Mobile, and even radio location.
Near the turn of the century in the early 1900's, radio was shared between those broadcasters backed by government or corporate entities. There were also those that took apart coils and whatnot out of Model T fords or whatever they could cobble together themselves, and used them for their radio equipment - aka amateurs.
Most of the activity was in the longwave and even AM broadcast bands up to about 2 mhz, where both commercial and amateur stations coexisted on the same bands, but eventually interference problems arose without any sort of regulation.
Amateurs were then assigned to the "useless" frequency bands for experimentation above the AM broadcast band, ie about 2Mhz and higher - designated as high-frequency, or HF.
The commercial and government stations didn't really realize the utility of HF with its capability for very long distance communications due to the ionosphere at first. Of course this changed very quickly so now everyone has access to HF, albeit with spectrum regulations to prevent the problem that existed with interference back in the turn of the century.
So amateurs, aka "hams" who are not sponsored by anyone but themselves, still exist, although they can be found across the whole variety of spectrum, not just HF anymore. Most don't have to rip apart coils out of their cars anymore, but the fact is it can still be done!
Just to a note to what Jay was saying... pick up a ARRL Handbook - but it doesn't have to be the 2010 version. The new version is kind of expensive but you can find a 2006-2009 version for 50-75% off the price (perhaps even more) than the latest 2010 version.
When you first pick one up, it may seem like the material is over your head, but trust me, it's *invaluable* to understanding how radio works.
You won't learn the material overnight, so be patient and just start with the basics and go from there.
i was in your seat about 4 months ago northrocks...i just googled the crap outta everything then read a lot of older forums threads in the hf dept. theres an awesome flash movie on single side band, upper and lower (ssb, usb, lsb) cw is continuous wave, so when u hear the "break in the wave" youre hearing what we call morse code....have fun