  Wireless networks are undergoing a transformative shift, driven by the
crucial factors of cost effectiveness and sustainability. Digital coding
metasurfaces (DCMs) might play a key role in realizing cost-effective digital
modulators by harnessing energy embedded in electromagnetic waves traversing
through the air. Integrated sensing and communication (ISAC) optimize power and
spectral resources by combining sensing and communication functionalities on a
shared hardware platform. This article presents a tutorial-style overview of
the applications and advantages of DCMs in ISAC-based networks. Emphasis is
placed on the dual-functionality of ISAC, necessitating the design of DCMs with
simultaneously transmitting and reflecting (STAR) capabilities for
comprehensive space control. Additionally, the article explores key signal
processing challenges and outlines future research directions stemming from the
convergence of ISAC and emerging STAR-DCM technologies.
