Estonian is the official language of the Republic of Estonia. Compared to other European languages, Estonian language is one of the smallest in respect of the number of speakers. However, if we take into account that 95% of languages (ca 4500 languages spoken in the world today) have less than 100 000 speakers, Estonian is a relatively widely spoken language.
Estonian belongs to the Finno-Ugric language family. Besides Estonian, the largest Finno-Ugric languages are Hungarian (14 million speakers), Finnish (5 million speakers) and Mordvin (900 000 speakers).
There are various options to learn Estonian:
If you're interested in studying the Estonian language more thorougly, University of Tartu offers a Master's program in Estonian and Finno-Ugric Languages, which is taught in English.