Simply supported slabs are supported on columns or stanchions. They have support on all four sides.
Simply supported slabs are classified as One way slabs and Two way slabs.
One way slabs bend in one direction only and transfer their loads to the two support beams in opposite directions. Their main steel in on shorter span length. L/B ratio is generally less than 2.
Two way slabs bend in both directions, and transfer their loads and stresses on all four sides. L/B ratio is equal to or greater than 2.
Simply supported slabs don’t give adequate provision to resist torsion at corner to prevent corner from lifting.
The maximum bending moment will be given if the slabs are restrained. But atleast 50% of the tension reinforcement provided at the mid span should extend to the support. The remaining 50% should extend to within 0.1Lx or Ly at the support as appropriate.