Text messages are a second-nature form of communication in the modern era, but there's a lot of complex technology going on in the background that lets the information from a text message leave your phone and become visible on someone else's.
Text messages channel information through a cellular tower, which is essentially a two-way radio that accepts and relays information to and from cell phones.
Radios emit what are known as radio waves, which are invisible and allow you to communicate back and forth with a radio. In this case, the radio is your cell tower, and anything you do on your cell phone gets sent to the tower to go off to where it needs to go.
To make sure your message gets to the right person, your phone transmits not only your message, but also information about your device to make sure it's being sent to the correct phone.
In just seconds, a message gets transmitted from your device, to a tower, to a converter, to another tower, and to the recipient's device, and it doesn't matter if they're international or not.
Text messages are a very useful tool that we take for granted, but without modern technology, they wouldn't be possible.