  This chapter reviews the construction of ``soft-collinear gravity'', the
effective field theory which describes the interaction of collinear and soft
gravitons with matter (and themselves), to all orders in the soft-collinear
power expansion, focusing on the essential concepts. Among them are an emergent
soft background gauge symmetry, which lives on the light-like trajectories of
energetic particles and allows for a manifestly gauge-invariant representation
of the interactions in terms of a soft covariant derivative and the soft
Riemann tensor, and a systematic treatment of collinear interactions, which are
absent at leading power in gravity. The gravitational soft theorems are derived
from soft-collinear gravity at the Lagrangian level. The symmetries of the
effective theory provide a transparent explanation of why soft graviton
emission is universal to sub-sub-leading power, but gauge boson emission is not
and suggest a physical interpretation of the form of the universal soft factors
in terms of the charges corresponding to the soft symmetries. The power
counting of soft-collinear gravity further provides an understanding of the
structure of loop corrections to the soft theorems.
