This bar chart displays the number of students enrolled in five different courses, with values ranging from 60 to 150. Each bar uses a vertical linear gradient that shifts from purple to blue, and hovering over a bar triggers both a color change to orange-pink and the appearance of a tooltip showing the course name and student count. The chart, rendered as an SVG, uses d3.scaleBand for the categorical x-axis and d3.scaleLinear for the numeric y-axis, with D3 v6 handling axes, data binding, and event listeners.