RF design stitching vias
So my question is if there is a difference on functionality between the two types of vias?

No there isn't. If you would ignore all kinds of effects regarding RF, current capability and reliability. Sure, you could use one via to connect one copper area or layer to another layer.

However, this would be a bad idea as one via isn't really a very good and/or solid connection. OK, it is good enough for a signal connection but to properly ground a large copper plate using many vias is preferred. That means "via stitching", similar to how pieces of cloth are stitched together to form clothes, you can use vias to stitch together copper layers.

That gives the advantages of:


better electrical connection (it can handle more current)
better thermal connection (better cooling of a chip for example)
better mechanical connection (instead of just a copper layer, the copper layer now "hooks" into the PCB).
a lower inductance connection (suppose 1 via is 1 nH, then 10 vias totals to 0.1 nH as they're in parallel, for RF design this is often a must do)
if one or more vias are broken, it is not a big deal as there are plenty of vias so improved reliability


The disadvantages I see is that the vias will have to be made so that means more drilling for the PCB manufacturer. Also due to lower thermal resistance in some cases soldering might be more difficult as the heat is pulled away more quickly.

But the vias are the same, stitched or not.