  In 2021 May, the Dark Energy Spectroscopic Instrument (DESI) began a 5 yr
survey of approximately 50 million total extragalactic and Galactic targets.
The primary DESI dark-time targets are emission line galaxies (ELGs), luminous
red galaxies (LRGs) and quasars (QSOs). In bright time, DESI will focus on two
surveys known as the Bright Galaxy Survey (BGS) and the Milky Way Survey (MWS).
DESI also observes a selection of "secondary" targets for bespoke science
goals. This paper gives an overview of the publicly available pipeline
(desitarget) used to process targets for DESI observations. Highlights include
details of the different DESI survey targeting phases, the targeting ID
(TARGETID) used to define unique targets, the bitmasks used to indicate a
particular type of target, the data model and structure of DESI targeting
files, and examples of how to access and use the desitarget code base. This
paper will also describe "supporting" DESI target classes, such as standard
stars, sky locations, and random catalogs that mimic the angular selection
function of DESI targets. The DESI target selection pipeline is complex and
sizable; this paper attempts to summarize the most salient information required
to understand and work with DESI targeting data.
