If you want to travel outside of the place you are from a passport is required. In this context, the place you are from refers to your country of citizenship.
Citizenship is granted if you are born in or move to a country and pass their requirements for citizenship (i.e., immigration). Why is this?
Living where you want to live
I wonder why I can’t just go and live anywhere on the earth, freely. Just pick up stakes (a reference to nomads and tents) and go where it pleases me, whenever.
There was a time in the earths history when one could do this, but it was a good idea to take weapons with you in case the people already there were not friendly.
And this is the reason for the current need for passports to control travel or immigration applications to change where you live. That is the people that were there first believe it is their place.
Of course, if you want to come to my place, you need to be invited or ask nicely. Arrival by force, a home invasion, is an option but most defend against it, hence why countries have armies.
Don’t Poop in my House
Ownership is human nature. Thiefs, uneducated and poor are not desirable in my home. They could mess it up and ruin my orderly and pleasant life style. And so, we define where your home is, and where mine is and we set immigration rules as to who can come and live in my house.
There are a lot of places on this earth I would like to live for a while but unfortunately I have to marry someone, be rich or smart or have desirable skills to do so.
I guess I could just sneak in and live there illegally but eventually someone would probably build a wall (yah Donald, I’m talking about you) and then maybe I couldn’t leave. You can check out, but you can never leave (Hotel California).
