  The High Altitude Water Cherenkov (HAWC) observatory is a ground-based
air-shower detector designed to study the TeV gamma and cosmic ray windows. The
observatory is composed of a densely packed array of $300$ water Cherenkov
tanks, $4.5$ m deep and $7.3$ diameter with $4$ photomultipliers (PMT) each,
distributed on a $22,000 \, \mbox{m}^2$ surface. The instrument registers the
number of hit PMT's as well as the timing information and the total charge seen
by the photomultipliers during the shower event. From the analysis of these
data, shower observables such as the arrival direction, the core position at
ground, the age and the primary energy are estimated, from which the energy
spectrum of cosmic rays and its composition can be studied. In this work, we
will describe the methodologies of HAWC cosmic ray analyses, including the
Bayesian spectral unfolding procedure used to determine the all-particle and
the light component energy spectra of cosmic rays. We will see that the
distribution of the shower age vs the fraction of hit PMT's contains
information about the composition of cosmic rays.
