Answer
$a.\quad $The interior of the sphere (including the sphere) of radius 1, centered at the origin.
$ b.\quad$ The exterior of the mentioned sphere.
Work Step by Step
$a.\quad $
$x^{2}+y^{2}+z^{2}=1$
is a sphere of radius 1, centered at the origin.
$x^{2}+y^{2}+z^{2} \leq 1$
contains points within the sphere (and the sphere itself).
$ b.\quad$
$x^{2}+y^{2}+z^{2} \gt 1$
describes all points outside the sphere.
