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This article will compare REST with the lesser known  GraphQL  style APIs. What is a REST API? REST (Representational State Transfer) is a client-server architecture style centred around resources and the state transitions can go through. A resource is named and located via a URI (Uniform Resource Identifier) . Usually, the HTTP transport protocol is used which give access to the standard HTTP methods/verbs allowing CRUD (create, read, update, delete) operations to be performed on the resources. The accepted CRUD operation to HTTP verb mappings can be found here .   For instance: curl -X GET http://api.com/users/1/photos/1 -H 'Content-Type: application/json' In the above example, the HTTP verb GET is used to indicate a read operation, the Content-Type:  application/JSON header indicates the desired representation. There are many more REST architectural constraints which would make an API truly RESTful but this is the general minimal you'll...

This is a large and somewhat confusing topic in software engineering. It doesn't help that we often abbreviate both terms to "auth", so first an explanation in plain English: Authentication : Are you who you say you are. Authorization : What you are allowed to do. It is useful to have the above one-liners in mind when thinking about these terms. Authentication is the act of confirming a claim to be true, authentic, real, genuine.  E.g. A person at airport claims to be Kye Yeung with a passport. The security guard authenticates this claim. Authorization is the act of giving permission to access resources. E.g. My nephew asks if he can play video games for an hour, I can authorize/give him permission to do so or not. This article will discuss a few popular internet security technologies but is by no means exhaustive. Basic HTTP Authentication Basic HTTP authentication , often abbreviated to "basic auth", is a protocol that requires client requests t...

Both technologies are concerned with virtualization, both need a piece of software to run, both have images, both are concerned with operating systems. So what's the difference between the two? According to Wikipedia "virtualization" is "the act of creating a virtual (rather than actual) version of something" . Very vague indeed, let's explore further. VM A virtual machine ( VM ) is hardware virtualization, it is a virtual computer, complete with ram, hard disk, CPU resource allocation. A VM  can be just this virtual computer, however an operating system is usually installed making it usable. Once a VM has been created it can be exported into VM image. The VM obviously can have any other application installed as you can like any other computer. In an execution environment a  VM is a "guest machine", run via a hypervisor/virtual machine monitor (VMM) on a "host machine". There are types of hypervisors, bare-metal (type-1) and ho...

There are many technologies to choose from for implementing a backend service and it's not immediately obvious which to choose. This article will compare the execution model of a few popular technologies, which is one of the key points to consider. Note I chose a rather vague term "technologies" as each technology describe themselves differently, framework, toolkit, runtime etc. "technologies" felt apt. To illustrate the differences I have implemented the same simple service in each of the technologies under consideration. These are Spring Boot 1.5.x  [1] , NodeJs  [2] , Spring Boot 2.x  [3] and Akka  [4] .The service contains a single '/books' endpoint that retrieves data from a Mongo DB. Spring Boot 1.5.x Spring Boot 1.5.x has one-thread-per-client-request execution module, synchronous and blocking. The following sequences of steps occur when the service  [1]  receives a client request `curl -X GET http://localhost:8080/boo...