From Distillers Wiki
Anise-flavored liqueurs are any of a number of liqueurs flavored with aniseed (though some varieties may instead use star anise or licorice). While all are dominated by the characteristic anise flavor, they vary considerably in sweetness and in the amount and types of additional flavoring.
Which drink is preferred varies largely by region, as most are tied closely to their place of origin. Nearly all have the interesting property of turning from translucent to cloudy when diluted: the oil of anise remains in solution when in the presence of a high concentration of alcohol, but crystallizes out of the solution when the alcohol concentration is reduced by dilution.