REST, GraphQL, SOAP and WebSockets Explained
REST, GraphQL, SOAP and WebSockets explained for beginners: how each protocol works, how they differ, and the concepts you need before testing them.
Track 2 of 9 in API 101, our free API testing course for beginners.
- For Manual testers
- For Developers
What is a REST API? The Definitive Guide
REST is the default API style on the web. Here's what it actually means — stripped of jargon and with runnable examples.
REST CRUD Explained: Create, Read, Update, Delete Walkthrough
CRUD is the heartbeat of REST. Create, Read, Update, Delete — walked through end to end.
PATCH vs PUT: The Difference That Trips Everyone
PUT replaces. PATCH modifies. Here's the subtle but critical difference — and why it matters for testing.
RESTful Best Practices: Conventions That Make APIs Predictable
Fifteen conventions that make REST APIs a joy to use — and the absence of any one is a smell.
What is GraphQL? A Practical Introduction for Testers
GraphQL lets the client decide what data to fetch. Here's how it works and when it beats REST.
GraphQL Queries vs Mutations: When and How to Use Each
Queries read. Mutations change state. Here's the divide — and how to write both correctly.
What is SOAP? A Modern Tester's Guide to a Still-Alive Protocol
SOAP isn't dead — it runs banks, insurance, and government. Here's how it actually works.
WSDL Explained: The Contract Behind Every SOAP API
WSDL is the WSDL — Web Services Description Language. It's the source of truth for every SOAP API. Here's how to read it.
What Is SOAP Testing? WSDL, Envelopes and Faults
SOAP testing is different. XPath, XSDs, SOAP Faults. Here's how to do it without losing your weekends.
WebSockets Intro: Real-Time APIs and How to Test Them
WebSockets are persistent, full-duplex, and weirdly under-tested. Here's a practical guide.
Practice these lessons on your own APIs.
The Free Developer License of Shift-Left API is a single-user license that renews free every 6 months. Import your OpenAPI spec, generate tests, mock APIs and run workflows on your own machine. Want the full guides first? Browse the API testing hub.