  I discuss two questions about the origin of star clusters: How long does the
process take? What is the mode of individual star formation? I argue that
observations of Galactic star-forming regions, particularly the Orion Nebula
Cluster (ONC), indicate that cluster formation often takes several Myr, which
is many local dynamical timescales. Individual stars and binaries, including
massive stars, appear to form from the collapse of gas cores.
