The terms “commercial radio”, “business band” and “business radio” loosely refer to a handful of voice services used by industrial operators. A common application is for a utility company where staff may be scattered across a wide region.
Equipment for these bands is generally simple, robust, and available on the used market. The only problem is that you cannot use it. These services are only available via FCC license, and for a legitimate business purpose.
They are a no-go for backcountry use.
Radio channels are available specifically for use by those who are flying or boating. Having dedicated channels makes it easy to put out a distress call, coordinate traffic in busy areas, or communicate with staff at airport and docks. These services work very similarly, although they do use different modes and frequencies.
The Aviation Radio Services category covers both aircraft and ground stations. As you would expect, it is used for coordinating take-off and landing at controlled airports. Planes can also contact each other while airborne, and channels are designated for specific purposes. Usage is also coordinated internationally.
If you are a pilot then you are already familiar with this service, so I do not need to explain it. If you are not a pilot then you should not be using this band, so I do not need to explain it. While this is an excellent band for use pretty much anywhere it is of no use to most backcountry travelers (except bush pilots, of course).
Another interesting (but useless for most of us) service is the Maritime Mobile Service. This is an interesting one since it encompasses not only channls for local use on very high frequency (VHF), but also channels for regional or even trans-oceanic use on high frequency (HF).
Much like with aviation services, you can go into stores and buy maritime radio gear, but you should not. Unless you are out on the high seas or large lakes with shipping traffic you should not be using this band (no, canoes do not count). Go buy a yacht and then you can get one of these radios.
And the point . . .
Typical backcountry travelers should not be using these services (yes, that means you). I mention them here because you do come across them occasionally.
Sometimes you will come across a person who has watched planes traveling overhead and thought about using an air-band radio as a sort of poor man’s satellite phone. He orders one online, starts carrying a radio on trips, and feels safer for it.
He is in for a rude awakening if he thinks that the jetliner who just picked up his SOS is going to go off-route and start doing circles overhead to stay in radio range.
Similarly, in coastal communities there is a bit of abuse that goes on with the maritime bands. In coastal communities these channels become a kind of “party line” for the locals. Such use is technically not appropriate, but as long as no harm is done the FCC looks the other way.
Here in Alaska both services are in widespread use, and both are widely abused, although not to the point of making them unusable. As you are learning about radios you should know what these services are, and stay off them.