Outer-grazer and inner-grazer are schemes of SunOrbits. All six diagrams show the Sun in the middle (the orange dot) and a putative planet's orbital band (in yellow). The latter is a ring whose inner radius is the planet's perihelion and its outer radius the aphelion.
Middle column, top: The minor planet's orbit enters the other planet's orbit from the inside without traversing it — it is an inner-grazer.
Middle column, bottom: The minor planet's orbit enters the planet's from outside without traversing it — it is an outer-grazer.