In languages like JAVA, we usually have to define the variable data types as well while declaring them but in PHP, we don't have to define the type of the variable while declaring it. Just give a variable any value. For example, we have variable $myFolks. You can set its value as under, say to a string:
$myFolks = "Hossayn opposed Tyranny of Yazid."
And then you can call it or print it and while doing so, you don't have to mention its data type. Afterwards, you can change data type as well:
$myFolks = 5+12+14
Or just $myFolks = TRUE