Note: Currently, this lesson teaches the Leaflet API. If you are looking for the previous materials on OpenLayers, see the Lesson 7 archive page [1].
Last week, you used a server-drawn image from a WMS to display your business layer (the farmers markets). This week, you'll learn about an alternative way to display your business layers on the map; namely, sending the raw data to the client (such as a web browser) to be drawn. This is a common technique in many web maps that can provide for much interactivity and potentially faster performance if used appropriately. You may have even been exposed to this practice when you reviewed a web map for your assignment last week.
This lesson describes two common formats used for sending vector GIS data to the browser (KML and GeoJSON) and shows how you can add these types of layers in Leaflet.