A quick review of beats: Adding 2 pure frequencies gives:
$$f(t)=e^{i\omega_1 t}+ e^{i\omega_2 t}$$
with the average frequency:
$$ \omega_0\equiv\frac 1 2(\omega_1+\omega_2)$$
and half-difference:
$$ \Delta\omega\equiv\frac 1 2(\omega_2-\omega_1)\equiv \frac{BW} 2$$
you get:
$$f(t)=e^{i(\omega_0-\Delta\omega )t}+e^{i(\omega_0+\Delta\omega )t}$$
$$f(t)=e^{i\omega_0 t}e^{-i\Delta\omega t}+e^{i\omega_0 t}e^{i\Delta\omega t}$$
$$f(t)=e^{i\omega_0 t}[e^{i\Delta\omega t}+e^{-i\Delta\omega t}]$$
$$f(t)=e^{i\omega_0 t}[\cos(-\Delta\omega t)+i\sin(-\Delta\omega t)+\cos(\Delta\omega t)-i\sin(\Delta\omega t)]$$
$$f(t)= [2\cos(\Delta\omega t)e^{i\omega_0 t}]$$
Which is a "pure" tone at $\omega_0$ modulated at $\Delta\omega$, as shown in wikipedia picture (https://en.wikipedia.org/wiki/Beat_(acoustics) ):
If we write it as:
$$ f(t)= A(t)\times e^{i\omega_0 t}$$
then
$$ A(t) = 2\cos(\Delta\omega t) $$
There is not a lot of information in that signal.
Suppose you can modulate $A(t)$ at all frequencies from $-\Delta\omega$ to $+\Delta\omega$? Fourier analysis tells that:
$$ A(t)=\int_{-\Delta\omega}^{+\Delta\omega}\tilde{A} (\omega')e^{i\omega't}d\omega'$$
Then:
$$f(t)=A(t)e^{i\omega_0 t} $$
and the frequency content is the convolution of the Fourier transforms of each multiplicand:
$$\tilde{f}(\omega)=(\tilde{A}(\omega)\circledast \delta(\omega-\omega_0))$$
The convolution just shifts the frequency content in the bandwidth from being zero-centered over to $\omega_0$.
In practice, that means we can encode information with bandwidth $BW=2\Delta\omega$ into $A(t)$. That signal is then used to modulate a carrier wave $\exp{i\omega_0 t}$ (with $\omega_0 \gg \Delta\omega$).
The ratio:
$$ \frac{\omega_0}{\Delta\omega}$$
doesn't really mean much, as long as it's bigger than one. That's usually an implementation consideration. For example, if you're operating an L-band radar at 1,500 MHz, you would like all of your signal to be 'radar', so you may go $+/-100$ MHz.
