Reading through this discussion I think there is a lot of phrases and jargon being used that may be confusing. 2 way radios and walkie talkies being good examples.
Here is my go:
Most people can get their head round the fm radio they have at home or in their car. This is a receiver. Somewhere near(ish) your home there is a transmitter pumping out a powerful signal that you receive.
A ham radio, walkie talkie or 2 way radio is a transmitter and receiver combined in one unit. You can transmit so someone can receive you and vice versa. Normally known as a transceiver.
There are a lot of radio frequencies that can be used. Some are better for one purpose compared to another. E.g. Your wifi internet uses a very very high frequency to transmit and receive large amounts of data. Your old am radio uses a low frequency as they tend to travel long distances better. Your fm radio picking up radio 1 would be using something in the middle.
Don't get too hung up on MHz etc. think of it a just a way of identifying different frequencies.
All of the different frequencies that can be used by radios are allocated to different users, many of whom pay for their use. If you try to use a radio that works on a frequency you are not allowed (licensed) for you could cause interference. Think blocking the ambulance service from communicating as worse case scenario. And would technically be breaking the law.
Amateur radio has been allocated a number of frequencies globally that can be used if you have a licensed. Some frequencies are good for long range communications. Some are better for short range local communications.
You can buy big radios more suited to sit on a desk or small hand held radios often referred to by people as walkie talkies. Normally the hand held radios are designed to work on the higher frequencies so are suited to shorter range communications. E.g. Around town or might even be limited to line of sight.
Of course there are always exceptions to this and I am generalising.
There are other types of radio services available without a license in most countries. In Europe there what is known as pmr446. These are the cheap (or sometimes not so cheap) hand held radios you can buy from a lot of shops. They work on quite a high frequency and are low powered so are only really useful for very short range communications. The general rule is, if you can't see them, you probably can't talk to them.
I have been a ham for nearly 20 years and enjoy being able to communicate with another ham at the other side of the world with a transceiver and an antenna that is basically a 20m length of wire. No internet or other infrastructure involved. Of course, the key point is "another ham". Some hams buy a commercially made radio and use it. Some build their own. It's a hobby that allows a lot of experimenting which is why I like it.
You can buy all sorts of radios starting from a few pounds. A lot of people (me included) are using the cheap Chinese hand held radios often found on ebay. The downside of them is that you have to know what frequency to program them for so that you can use them. Out of the box they are not setup for any particular usage or license so shouldn't be used until programmed to a frequency you know you are allowed to use.
There is also a group out there who are buying amateur radio kit for when the SHTF thinking that in a disaster they will not need a license. The downside of this is that if you haven't used the kit until it's an emergency you will probably struggle to get the most out of it or anything at all. If you are going to buy some kit, you may as well put the effort in to get a license so you can practice with it.
I hope that all helps. I would recommend that anyone who is interested contact their local radio club. You can get you foundation license in a weekend and it will give you a good insight into what is involved and the ability to use a variety of radio frequencies. But then I am biased
