https://cwe.mitre.org/data/definitions/98.html
The include statement takes all the text/code/markup that exists in the specified file and loads it into the memory, making it available for use.
For example:
`File 1 --> vars.php`
`<?php`
`$color = 'green';`
`$fruit = 'apple';`
`?>`
`#############################################`
`File 2 --> test.php`
`<?php`
`echo "A $color $fruit"; // output = "A"`
`include 'vars.php';`
`echo "A $color $fruit"; // output = "A green apple"`
`?>`