While determining the electric field due to a uniformly charged conducting or non-conducting sphere,does the sphere is considered hollow or it is considered solid?
Can anyone really state , what is meant by "thin spherical shell/thin sphere"?
Before we talk about the term "spherical shell" and "thin sphere", let us talk about the possible cases of the sphere itself.
Generally speaking, it depends on what is given to you.
Keep in mind that whether it was hallow or not, for a conducting sphere you will always have $\rho _v=0$ and all the charge distributed at the surface as $\rho _s$.
Now, a spherical-shell is simply a 3-D spherical shape defined as the region between two concentric (empty) spheres. Just like the area between two circles but in 3-D.
A charged spherical shell cut-away section may look like the image here, with thickness being very small relative to the diameter.The thickness is the conducting portion and the charges should be accumulated on the outside of this hollow sphere, with zero charge inside the hollow portion.