A line chart tracks the cumulative number of unique logged-in VizHub users over time, from the platform’s launch on August 14, 2018, through March 2022. The y-axis shows user counts, while the x-axis represents the timeline, with annotations marking key events such as a Medium post, the VizHub 2.0 Kickstarter, and the Datavis 2020 launch. The visualization uses D3 v4 with an SVG rendering, leveraging `d3.scaleTime()`, `d3.scaleLinear()`, and `d3.line()` to map the data from a CSV file.