What is the main difference between a one way slab and two way slab?

one side beam is one way slab and two side beam 

bearing points, steel in tension, support dimensions

1.  In One way slab Ly/Lx ratio >2.0 But 

In Two way Slab Ly/Lx ratio less than equal to 2.0

•   In one way slab the bending takes place in one direction only i.e. Shorter Span.
• In two way slab the bending take place in both direction.

İf the ratio of longer span lenght to shorter span lenght is equal or more than2, we call that kind of slabs as a one way slab is provided by main reinforcement just in short direction. however İf  the ratio is less than2, we call that kind of slabs as a two way slab is provided by main reinforcement both in two direction. Also Moments disturbution coefficient depends on both the ratio and restrain condition of slabs. You can look at this table for moment disturbution ratio in slabs.

A one way slab is supported by beams only on two opposite sides while a two way slab is supported by beams on all sides .

at a one way slab the loads are carried along one direction. The loads are carried along both directions at a two way slab

One way is directly single reinforecement means one layer bothways while two way slab is two layer reinforcing steel both ways as design with bent down bars specifically appled from or at  L/4  from the the face of  perimeter supporting beams