I found it quite hard to find some programming specific symbols on google, so that we can learn about them.
So, and by guessing, I end up finding token keyword. 
Parser Token. Magic Words.
For someone that, may have the same difficulties here’s a fine link:
http://php.net/manual/en/tokens.php
Márcio
You mean I have to keep them straight?! Aww!!! 
Here’s a link to the Arrow Operator: http://ch2.php.net/manual/en/language.oop5.static.php
There is a link on that page for the scope operator.
Getting your programming languages mixed up there, David? 
-> is called something like a postfix expression. It’s used when a pointer is accessing a child of itself like a class. It’s the alternative for (*name).child. Rather, it can just be name->child.
:: is the scope operator. It’s used for things like namespaces, so if you have a namespace mine with a function yours, then you could access it such as mine::yours. If you were to just go ::yours, then it would look for a function (or variable) in the global scope.