A language that is not related to any other language is called language isolate. A language family comprises languages that seem to have developed together. They may have similar vocabulary, sentence structure or grammar. e.g. English belongs to Indo-European language family comprising languages such as English, French, Portuguese, Russian, Danish, Dutch, Spanish.
A language isolate does not belong to any family. One such language isolate is Burushaski. Spoken in Gilgit-Baltistan & Hariparbat of Kashmir region, Burushaski has its distinct dialect which is different from any other language spoken across the world.
A few people from Burushaski speaking communities have attempted to preserve the language.
In 2017, a 100 year old Burushaski scholar , Nasir Al Din Nasir Hunzai passed left for heavenly abode. He was revered with the title of Baba i Burushaski( father of Burushaski) owing to his service to the language. He worked with a German university to develop dictionaries for Burushaski to German and English.
However, a researcher in an Australian University, Prof Ilija Casule, theorized in 2012 that Burushaski belonged to Indo European family. Being supported by Eminent historians it could be a path breaking discovery awaiting a final approval among researchers.