Karolina is the Scandinavian and Slavic form of Caroline, the French form of Carolus which is the Latin form of Charles,the English form of Old High German Karl meaning “man, husband” via Proto-Germanic *karlaz (free man), of uncertain etymology but likely deriving from a PIE origin. It was originally used to refer to men who were not thralls or servants but who still lived at the bottom of society, thus connoting the idea of a “free man”, those who were not tied down to a lord or to the land, able to go wherever they wanted.
Elena is a female given name in several languages, a cognate of Helen. In Greek mythology, Helen (Helene in Ancient Greek) is the name of a daughter of Zeus and Leda, considered to be one of the most beautiful women in the world whose kidnapping by Paris led to the 10 year Trojan war.
The origin of Helen is unknown- it’s been linked to Ancient Greek helene meaning “torch”, likely in reference to something that shines or illuminates, so the name would essentially mean “the shining one” or “the bright one”; another possible origin is from Ancient Greek selene “moon”, which would tie it to the idea of illumination and light.
Elena is also a variant transcription of Yelena, the Russian form of Helen.
Origin: uncertain, though it may be derived from a pre-Greek source
Meaning: uncertain, though it’s been linked to Ancient Greek helene “torch” or selene “moon”, essentially meaning “the shining one” or “the bright one”