Weekend Reads - API Testing (Web Service Testing, Inspect Http request, Rest API Testing) - Free tools

Very good presentation on compiled list of free tools for API Testing. More Details - Free API debugging and testing tools you should know about

Tools List from the presentation and SO reads

• Rest-assured - Java DSL for easy testing of REST services
• Retrofit - A type-safe REST client for Android and Java
• RequestBin - Inspect HTTP Requests
• Hurl.it — Make HTTP Requests
• ngrok captures all traffic - Raw request/response bytes
• mitmproxy: a man-in-the-middle proxy - Intercept, modify, replay and save HTTP/S traffic
• Postman is a powerful HTTP client to help test web services easily and efficiently
• Mock your HTTP responses to test your REST API
• Chrome Rest Console - REST Console is an HTTP Request Visualizer 
• SO - Online testing a REST service
• Simple REST and HTTP API Client for .NET

While reading through the list again went back to check on SOAP, Rest Basics. API testing / Web Service testing we will be looking into only aspects Rest, SOAP based web services. Summary based on StackOverflow readings, posts. References - StackOverflow reference answers link. More details Pls check reference link. (Consolidated Answer and Detailed short summary listed below)

Rest	SOAP
REST is over HTTP. REST has no WSDL interface definition	SOAP can be over any transportprotocols such HTTP, FTP, STMP, JMS etc.
REST stands for Representational State Transfer. REST approach uses the standard GET, PUT, POST, and DELETE verbs	Simple Object Access Protocol (SOAP)  SOAP builds an XML protocol on top of HTTP  / TCP/IP.
REST is good for getting a blob of data that you don't have to work with	SOAP describes functions, and types of data. If you want to get an object, SOAP is way quicker and easier to implement
Typically uses normal HTTP methods instead of a big XML format describing everything	Has several protocols and technologies relating to it: WSDL, XSDs, SOAP, WS-Addressing
REST plays well with AJAX'y web pages. If you keep your requests simple, you can make service calls directly from your JavaScript, and that comes in very handy.	SOAP is useful from a tooling perspective because the WSDL is so easily consumed by tools. So, you can get Web Service clients generated for you in your favourite language.

More Reads

HTTP vs REST vs SOAP

REST and SOAP: When Should I Use Each (or Both)?

From AWS Blog - 80% REST / 20% SOAP usage pattern

Example - Learn REST: A Tutorial
Restful Load Testing

Happy Learning!!!