This is the 1132nd most frequent Russian word.
анна
"Анна" is a Russian female name, equivalent to "Anna" in English.
The word 'Анна' is used as a proper noun, being the name of the person performing the action of reading.
Анна читает книгу.
Anna is reading a book.
The word 'Анна' is inflected into 'Анне' to signify the dative case, indicating the indirect object of the verb 'дал'.
Я дал книгу Анне.
I gave the book to Anna.
The word 'Анна' is inflected into 'Анны' to signify the genitive case, indicating possession.