How does a cell phone or smartphone actually work?

There are two inventions mostly that allowed cell phones and smartphones to actually work in real time. 

First of all it's GPS satellites. Fighter jets were moving to fast for normal navigation and started to run into each other because of their relative speed and the lack of forgiveness in the sky in fighter jets, bombers and passenger jet liners. So, somewhere in the 1970s GPS "Global positioning Satellites" were invented to help prevent so many jet crashes around the world. 

For example, If I had had a GPS handheld device in 1970 when caught in a blizzard white out I might have been able to at least get back to my car even though the road was covered over with 5 to 7 feet of snow at that point and not almost frozen to death on Mt. Shasta with my two buddies on Christmas Vacation then. But, the GPS satellite systems were not even invented at that point in 1970. We only survived this situation because we dug a snow cave so the wind didn't freeze us to death in the blizzard white out. You couldn't even see your hand in front of your face in this whiteout so you really didn't know where you were exactly.

At least then we could have started up my 1966 Seablue VW Bug and moved the snow away from the engine compartment and turned on the engine and heater and not almost frozen to death in a snow cave then. 

When we finally found my bug the next day all I could see was the top 3 inches of the radio aerial above the snow.

So, having a GPS handheld device might save your life along with a Iphone 14 or above that has an emergency satellite phone built in when you call 911. So, you can literally be rescued anywhere on earth even out in the middle of the ocean with this satellite emergency device available that bounces a signal off Satellites to rescue you and to pinpoint your exact location on earth.

So, GPS satellites allow you to make phone calls all over the world.

The 2nd technological development that allows a cell phone or Smartphone to work is we went from analog to digital signals for phones and internet and sound and CDs and music a lot.

This allowed what I might call "The ability to boost signals over long distances". Analog is much harder to boost than digital signals because digital signals are ALWAYS only Zeros and Ones. Nothing else.

So, boosting zeros and ones is much easier than boosting analog signals so these two inventions mostly made it possible for cell phones to work.

The third thing I should mention is that Microwave towers and ways to send digital signals through microwave towers allowed phone calls to places that had no copper phone lines going there to some degree. So, finding ways to send digital signals through microwave towers was the third really important invention to allow Cell phones and Smartphones to work many places on earth.

So, you have a cell phone or Smartphone and when you dial a number it sends a signal to the nearest Microwave tower. Then the GPS locator for the other phone if it is turned on anywhere on earth  is located by Satellites wherever it is on earth. The satellites then tell that calling microwave tower the location of the nearest cell tower to the phone receiving the call anywhere on earth because they have located The GPS signal of who you are calling. 

Then if possible and reception on both ends is good enough you can talk to whoever you want to good enough anywhere on earth. This is a simple way to explain how Cell phones and Smartphones all work.

Of course there are many other inventions both software and hardware like Chips and other things that are involved in all this working too. and your battery needs to be charged on your phone and your phone bill has to be paid too on both ends for this to work seamlessly worldwide.