This tutorial teaches how to create a custom data visualization with ReactJS using the Recharts charting library to display time series data stored with InfluxDB. The author explains what Recharts and InfluxDB are, provides an overview of their features, and then demonstrates how to use them together in a practical example. The tutorial covers setting up InfluxDB, installing project requirements, writing data to InfluxDB, querying data from InfluxDB, and visualizing the data with Recharts. It also suggests ways to extend the project for further learning.