Some Iranian dictionaries online include dictionary-farsi.com and farsidic.com. To use these websites, one must enter a word or phrase in English in the blank space provided and then press "search." Then, a translation of the word or phrase is provided in the native Iranian language.
Dictionary-farsi.com is used to translate Persian to English as well as English to Persian. Farsidic.com only allows English to be translated to Persian. Dictionary-farsi.com allows words or phrases while farsidic.com only allows single words.
Both of these websites use the word "Farsi" as the name for the native language of Iran. Both "Farsi" and "Persian" mean the same thing. Iranian people who live in English-speaking countries are the only group of people who use two different terms to refer to their language.