How is data sent in REST web services - api

Question

I am learning about web services. I now have good understanding of SOAP. I have few questions regarding REST web services.
1) DO GET, PUT & POST methods in REST web services work exactly the same way as they work with a simple website.
2) GET , PUT & POST methods in REST web services allows us to send/Receive data(say: tweet in Twitter) between client & the web service. Is this message sent(PUT & POST) & Received(GET) in the Body of the POST/PUT method in XML/JSON/other formats or is the file(in a specific format) sent separately.
3) Are there any Browser tools available to see what is Sent & Received in REST web services.

Answer 1

First of all, clarifying a few things. REST is an architectural style, a set of constraints to guide your structural design decisions. REST is not coupled to any particular underlying protocol, so it's not dependent on HTTP, although it's very common.
Second, keep in mind that REST became a buzzword to refer to almost any HTTP API that isn't SOAP, and most of the so called REST APIs aren't REST at all. Most of them are simple RPC over HTTP. I recommend reading this answer for some clarification on that.
Now, to your questions:
1) DO GET, PUT & POST methods in REST web services work exactly the
same way as they work with a simple website.
The problem with your question is that the only exact definition of how those methods work is the one defined by the RFCs, and a simple website might implement it differently. For instance, PUT isn't allowed to be used for partial updates, but many websites and HTTP APIs do that.
As I said above, REST is protocol independent, but respecting the uniform interface constraint and applying the principle of generality, you should stick to the standard semantics of the underlying protocol as much as possible, which means that if you're using HTTP 1.1, you should stick to the behavior determined in the RFCs 7230 to 7235.
2) GET , PUT & POST methods in REST web services allows us to
send/Receive data(say: tweet in Twitter) between client & the web
service. Is this message sent(PUT & POST) & Received(GET) in the Body
of the POST/PUT method in XML/JSON/other formats or is the file(in a
specific format) sent separately.
The format is established in a previous contract between the client and server -- usually in the documentation -- and it's handled during the request using the Accept and Content-Type headers. For instance, if a client wants JSON response, it sends the Accept: application/json header. If the server can't respond with JSON, it should fail with 406 Not Acceptable.
Keep in mind that in an actual REST webservice, you don't use a generic media-type like application/json since that says absolutely nothing about the content other than how to parse it. You should have more specific media-types for your resources, and focus your documentation on those. For instance, an User resource in JSON format can have a custom media-type like application/vnd.mycompany.user.v1+json.
3) Are there any Browser tools available to see what is Sent &
Received in REST web services
In Google Chrome you can use the developer tools, or some client like this or this. You can also use a command line client like curl.
Also, keep in mind that it should be pretty easy to drop-in a generic html+javascript client into a real REST API to make it navigable with a browser. Here is an example of a REST API using HAL+JSON and a generic client.
https://api-sandbox.foxycart.com/hal-browser/browser.html#/

Answer 2

1) Yes, REST functions pretty much exactly the same as a normal HTTP website, for example, GET would retrieve data without changing the state of the server and POST would send data to the web service as a new 'Object', and PUT would modify an existing 'Object'
2) You would enclose the data to be sent inside the body of the request for POST and it would return data back in the body. GET does not accept any data in the body (and you would specify it as part of the path/query parameters ie http://service.com/rest/directory/user1?param=something) but would return the results of the query inside the body. POST would require a message to be posted in one of the forms specified as accepted, most usually JSON. Specifying the Content-Type would indicate to the web server what type of data you are sending and the Accept header would indicate what type you wish your response to be in.
3) In Google Chrome you can use the Developer Tools (Ctrl+Shift+I in Windows) and go on the Network tab to see what is sent and received as a page is loading/performing tasks. You can use DHC or RestEasy to send your own custom requests to REST Services through a GUI, or cURL to do this through a command line

Answer 3

DO GET, PUT & POST methods in REST web services work exactly the same way as they work with a simple website?
yes. they are same anywhere we are using http. read this article specially Request Method section
GET , PUT & POST methods in REST web services allows us to send/Receive data(say: tweet in Twitter) between client & the web service. Is this message sent(PUT & POST) & Received(GET) in the Body of the POST/PUT method in XML/JSON/other formats.
yes they are generally in these formats but can be in any depending on ur requirement.
read this ans for better understanding of content-type and headers in general
Are there any Browser tools available to see what is Sent & Received in REST web services.
as mentioned in one of the comments. Postman is an awesome chrome extension. I generally preffer fiddler over Postman but it is not a in browser tool.