Introduction to Node-RED

The website of Node-RED (https://nodered.org/) gives a perfect introduction to the purpose of using the software:

Node-RED is a programming tool for wiring together hardware devices, APIs and online services in new and interesting ways.

It provides a browser-based editor that makes it easy to wire together flows using the wide range of nodes in the palette that can be deployed to its runtime in a single click.

Hence, we can say that Node-RED is a UI-based programming tool that can be used to create various applications, which include hardware device control (Raspberry Pi GPIO access is also available), flow-based API development, and so on. We can run multiple flows at once and each of them will run independently.

Moreover, Node-RED allows the easy setup of several additional services, which would otherwise require a lot of work and experience. One such example is setting up a SQL database to store all the data arriving in Node-RED through any communication...