Difference between Webservice ,Remoting , WCF.Net 3.5

Web Services..
1.It Can be accessed only over HTTP
2.It works in stateless environment
3.It support only the datatypes defined in the XSD type system, limiting the number of objects that can be serialized.
4.It support interoperability across platforms, and are ideal for heterogeneous environments.

.Net Remoting..
1.It Can be accessed over any protocol
2.Provide support for both stateful and stateless environments through Singleton and SingleCall objects
3.Using binary communication, .NET Remoting can provide support for rich type system
4.It requires the client be built using .NET, enforcing homogenous environment.

WCF is the Windows Communication Foundation which is shipped along with Dot Net 3.0/3.5. User's having 2.0 framework can make use of WCF by installing the MS add-in component for WCF. WCF comes up as a replacement for Remoting and Web service in dotnet.
The main feature of WCF is it's security. It can use the protocols like basice,wsHttp,tcp...wsHttp comes with default windows based security feature. WRT web services WCF works with the industry standard Contract based protocols.
The componets WCF are data contract, Service Contract and the Service programme. WCF also supports many of the advanced WS-* Web service standards, which can provide rich Web service communication across platforms. WCF can be extended to use protocols other than SOAP to communicate with Web services, for example, Rich Site Summary (RSS). It is interoperable with WSE 3.0, System.Messaging, .NET Enterprise Services, and ASMX Web services.This means that, with little or no change to code, existing applications that are built with these technologies can interoperate with WCF services. WCF contracts define the behavior of WCF services. They are created in code by service developers, and are exposed to clients in the service metadata.

The five types of contracts:
Service Contracts
Operation Contracts
Data Contracts
Message Contracts
Fault Contracts

WCF is flexible because its services can be hosted in different types of applications. The following lists several common scenarios for hosting WCF services:IISWASSelf-hostingManaged Windows Service