Soap is a protocol it follows rules for requests and responses i.e requests and responses have envelope , header tags and body tags and other tags etc., But Rest usually is not considered a protocol. It is architecture.

Rest does not have requests and responses as they are in Soap.In rest request can be as simple as sending the username and password in the URL and response can be a simple response as well which can be seen in the browser

But in order to send soap request and response we need to load the WSDL of soap based web service into SOAPUI tool, fire the soap request and then only can see soap response and that too in the tool only.

Soap response can be xml based only while rest response can be based on xml or JSON(java script object notation)

Rest requests used http i.e we can simply fire these http requests on our browser to connect to the server.

We can go to this url to see a sample rest request and response.

The url is a sample rest request and the response we get in browser is a sample rest response in the form of JSON.

So once again REST is an architecture, it is informal and request is http based ,sent over browser and response is either based on XML or JSON.