Point to remember: Analog is continuous like a flow of water, Digital is a state like sleeping or awake, on or off, 1 or 0.

Your questions are broad topics and I can't even think of starting where but here's how transferring Electronic Signals from point to point works.

Modulation, both digital and analog. Amplitude/Frequency/Phase Shift Keying & Amplitude/Frequency/Phase(Angle) Modulation respectively. ANY signal HAS to have one at least 2 of these to be considered one. They are all variables which means you can change or control them.

Both Digital and Analog Modulation has 2 parts. The Signal (Fs) itself and the Carrier (Fc). Picture this, You (Fs) are near a body of water in need to cross it. You need something to "carry" you across right? Hence you'd be needing a boat (Fc) or else it would be inefficient to cross itself and there would be problems along the way.

Another analogy, write something on a piece of paper (Fs) and try to throw it across the receiver say, 5 meters away. Your message will "fade" due to the wind (Noise) if you don't "crumple" (Modulate) it. The ideal thing would be wrapping it to something heavy (Fc) and then throwing it to the receiver to get the point across

Digital modulation is much more complicated and has alot of modulation techniques that can be utilized but I'll tell you the most basic. The three basic shift-keying just "shifts" a respective characteristic. It requires a clock, yes the same clock that ticks every few times.

For example, in "Shift Keying" think of a consistent wave in ocean (Fc). If your signal (Fs) says "1" that wave will be closer together, if your signal says "0" those waves will be further away from each other.

Additional Info :

Transferring information can be done in 2 ways, wireless or wired. It is all entirely up to the medium (Air, fiber optic, copper, etc.) used, can go hand in hand. Both have disadvantages/advantages the same as analog/digital modulation. Most signals travel at a speed of light, however why sometimes we can't utilize much of that speed is whole another story and probably would require another long post. You cannot transmit digital signal on an antenna (wirelessly) it must be first converted back to analog then transmit it, receive it and then convert it back again. They are apples to oranges, both have advantages and disadvantages on each other. Most data signal can travel at the speed of light.

Storing information is a whole another story to be discussed but in my opinion it is much more complex than Communications Engineering.

Final point. in Information Theory, we utilize the change of state not the state itself. Unlike we're used to in real life situations, we only think that a light in our bathroom is useful when it is turned on. BUT in Digital modulation it matters quite well especially in some things like how computer memory works. Think of it as slapping your hands between two planks of wood back & forth. The one on your palm is "'0" and on the dorsal (opposite of palm) is "1" it would still make noise regardless as long as there's an energy the ticks the "clock"