This is the common name for the introductory section of the Doctrine and Covenants
The Lord's Preface
The first edition of what is now the Doctrine and Covenants was published in Kirtland, Ohio, in 1835 under this title.
What is the Book of Commandments
This section of the D&C, which Joseph Smith received in Liberty Jail, is often cited for its teachings on righteous leadership and agency.
What is Section 121-123
D&C Section 13 is a short section that contains the words of this being, who conferred the Aaronic Priesthood upon Joseph Smith and Oliver Cowdery.
Who is John the Baptist
This final, non-numbered part of the current Doctrine and Covenants includes declarations on two topics: the Manifesto (ending plural marriage) and the revelation on the priesthood
What are the Official Declarations (or Official Declarations 1 and 2)