This bar chart shows the distribution of employees across departments, with each bar representing a department's headcount. The visualization loads CSV data from a remote URL and processes it using D3's `csv` and `scaleBand`/`scaleLinear` to map department names to bar positions and employee counts to bar heights. React manages the component state and rendering lifecycle, while D3 handles the SVG coordinate system, axes, and tick formatting. The chart includes labeled x-axis categories, a y-axis with gridlines, and uses a fixed width/height with margins for clean spacing.