From: Eduardo S.
What’s the diference between regular variables defined as, lets say
“example”, and the ones defined as “:example” ? If there’s a
when should each case be used?
Items that start with a colon are not variables, they are Symbols.
Continue your research with that bit of information; there’s a lot out
there on the difference between Symbols and Strings (in 1.8), and when
to use them.