The export command is mostly used when setting up a new PATH.
You need to export a variable, in order to use it globally. By default, a variable can be used only local, unless it is exported.
$ x=/home/razvan
$ echo $x
/home/razvan
Start a new shell and display the value:
$ bash
$ echo $x
# you will get a new line as an output
Export the variable in order to use it globally:
$ export x=/home/razvan
$ bash
$ echo $x
/home/razvan