Originally posted by Arjun Reddy: I am just trying to find out if what I understood is correct. is it?
You aren't quite there yet. Here are some nits
You can't compare RPC and Document/literal. You can compare messaging styles (RPC vs Document), encoding styles (encoding vs literal), or messaging modes (e.g. RPC/literal vs Document/literal)
"Cannot validate the request to the web service" - should most likely be Cannot validate message payloads with XML Schema. Document/literal payloads can be validated entirely through XML schema, RPC/literal payloads have to take the WSDL's message composition rules into account (so the validator would have to be WSDL aware), and the encoding of RPC/encoding is outside of the scope of XML Schema and WSDL.
You are not considering the the "Wrapped Document/literal" convention which describes an informal RPC-oriented payload document format that is fully validatable through XML. It's just not being that honest about being "RPC".