What is mean by connected system?
It’s a system where one application is distributed across multiple systems/machines. Each machine run the part of application.
What is mean by service?
Service is a self-contained business functionality. It does one complete business functionality for us.
Does Services and .net web services same?
No. Service is a generic term and Microsoft or .net web services is just a mean of implanting them.
What is Service Oriented architecture?
It’s an architecture style for building business applications using services which communicate via standard messages.
What is the difference between HTTP and SOAP?
HTTP is transport protocol used for communication across internet.
SOAP is a messaging protocol, a commonly agreed standard format using which messages will be transferred during service communication
Does SOAP and XML are same?
No. Xml is more generic. It is used to describe data.
SOAP is more specialization of xml. Fixed structure, for instance at the top there will be Soap header and then soap body etc.
What is WSDL?
WSDL or Web service description language which is based on xml and which will be used to describe web services. It basically describes the location of the service and the operation service exposes.
You can also read this WCF interview question which talks about the difference between XmlSerializer and DataContractSerialzier.