Web Services Questions

Hello Everyone,

I am looking to ask some web services related questions where I didn't get the exact answer till now. I have google it to find them and I have found some blogs like this https://hackr.io/blog/web-services-interview-questions. Can anyone explain to me about below questions query:

1. Give me an example of real web service?
2. Define each of these layers of protocol stack?
3. Define XML – RPC?
4. Differentiate between web services, CORBA and DCOM?
   I have a few interviews on next week and I am preparing myself to crack this. Can anyone suggest me some tips?