Symbols

	- symbols are not strings, but string could be converted to symbols and vice versa
	- even this is possible:
		- value = "and"
    	- symbol = :"cats #{value} dogs"
    - comparing symbols to symbols and symbols to strings:
    	a = :symbol1
    	b = :symbol1
    	a.object_id == b.object_id => true
    	a == b 					   => true
    - again, coz symbols are not strings, fancy string operations are not allowed on symbols
    	examples:
    		- :simple_symbol.respond_to("reverse") => false
    		- :cats + :dogs => throws a NoMethodError