This example displays a week of temperature readings for multiple cities, with each city represented by a colored line that conveys its temperature trend over time. A legend identifies the color associated with each city. The visualization uses d3.line with curveBasis for smooth paths, d3.scaleTime and d3.scaleLinear for axes, and d3.nest to group the CSV data by city. d3.scaleOrdinal with schemeCategory10 assigns colors, while custom legend and axis components are built using SVG.