SOAP VS POST VS GET

When do we use each of these and how to decide which one better than the rest on
any given situation? Thanks in advance.

Hi netBoyzz,

The GET method means retrieve whatever information (in the form of an entity) is
identified by the Request-URI. If the Request-URI refers to a data-producing
process, it is the produced data which shall be returned as the entity in the
response and not the source text of the process, unless that text happens to be
the output of the process.  it can only transfer some data in querystring of
url. 

Post operation can transfer more data , POST method is used to request that the
origin server accept the entity enclosed in the request as a new subordinate of
the resource identified by the Request-URI in the Request-Line. POST is designed
to allow a uniform method to cover the following functions.

Webrequest can use both get and post method, soap can only use post method, 

Best regards,
Guang-Ming Bian - MSFT