Hi!
I have a vSphere environment running and i'm just starting out with the vSphere APIs and SDKs in C#. So i startet reading with Getting Started with vSphere SDKs and downloaded the SDK and API packages.

First i got PowerCLI with the vSphere SDK for .NET and read through the vSphere SDK for .NET developer's guide. Then i downloaded the vSphere web services SDK package, compiled the samples and dlls and am now reading through the programming guide.
But still the overview which API/SDK is best for what and how to use it is missing.

Am i right in the assumption, that both vSphere SDK and vSphere Web Services SDK depend on vSphere API which is available on each ESX host?
I found the vSphere API reference but it seems to me that both, samples from webservices SDK and vSphere SDK, use the same objects and methods from vSphere API directly.
The only difference i found out is, that the web services examples use AppUtil which again uses vSphere API but vSphere SDK doesn't. Is that right and where is the advantage in using one of the SDKs instead of vSphere API? In case of using web services SDK, have i to use the AppUtil out of the samples?

So you see, i'm a bit confused by the possibilities and usage. Especially the difference between vSphere SDK and vSphere Web Services SDK is not clear to me.
Can you help me by summarizing briefly the differences and purposes of those packages? Or is there a good document which treats that topic?

Thanks and regards
Patrick