This interactive scatterplot visualizes Iris flower measurements, plotting sepal length against sepal width for three species. The React-based interface uses D3.js scales (scaleLinear, scaleOrdinal) to position and color each circle. A custom ColorLegend component responds to mouse hover events, highlighting the selected species by fading all other points to 20% opacity. Hovering a legend item filters the visible marks, while tooltips display exact values. Data loads asynchronously from a CSV file using d3.csv.