This is the 1373rd most frequent Russian word.
светлана
"Sветлана" is a Russian female given name, meaning "light" or "pure."
Here, 'Светлана' refers to a person's first name, a proper noun used in a nominative case as the subject of the sentence.
Светлана пошла в парк.
Svetlana went to the park.
Here, 'Светланы' is the genitive case of the proper noun 'Светлана', indicating possession or relation.
Этот подарок для Светланы.
This gift is for Svetlana.
Here, 'Светлану' is the accusative case of the proper noun 'Светлана', marking it as the object of the verb.