  Gravitational waves emitted from the coalescence of neutron star binaries
open a new window to probe matter and fundamental physics in unexplored,
extreme regimes. To extract information about the supranuclear matter inside
neutron stars and the properties of the compact binary systems, robust
theoretical prescriptions are required. We give an overview about general
features of the dynamics and the gravitational wave signal during the binary
neutron star coalescence. We briefly describe existing analytical and numerical
approaches to investigate the highly dynamical, strong-field region during the
merger. We review existing waveform approximants and discuss properties and
possible advantages and shortcomings of individual waveform models, and their
application for real gravitational-wave data analysis.
