Answer
$ a.\quad$ The interior of the sphere (including the sphere) of radius 1, centered at the origin.
$ b.\quad$ The exterior of that 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 inside the sphere (including the sphere itself).
$ b.\quad$
$x^{2}+y^{2}+z^{2} \gt 1$ describes all points outside the sphere.
