The purpose of welded wire mesh in a concrete slab is to reduce the degree of cracking if control joints are absent or too far apart.

The purpose of fibers in a concrete slab is to reduce plastic shrinkage cracking.

Rebar might be used where an additional load is expected.

Whether the slab designer wants to use one or more or none of these reinforcing materials, none is a substitute for the other.

Thank you Renovator. The rebar would go into the footings and some kind of wire mesh would go into the five inch general slab areas.