By setting map and layer properties, you can enable the functionality that's important to your audience and improve the overall appearance of your map. Map properties include bookmarks, the organization of layers, time settings, and tools and capabilities for apps. Layer properties define the display and attribute characteristics of the layer. For example, you can change the transparency, apply filters on features, set the visible range, refine the imagery display, and so on. For layers you own and have added to the site, you can save many of your setting changes as properties of the item.