Okay. Let me show you how each of these elements looks like. Let's start with points. So, points are an extremely common mark used in visualization. Common example of the use of points is in scatter plots. Right? Like the one that I've just shown you. So, every single dot represents a data item, and typically its position represents two values. Points are also used in other visual presentations, another very common one is on top of maps. So, if you have a map, I'm not particularly good at drawing boarders, so I'm inventing on the fly here. So, imagine these are regions on the map, and there are events or something happening in certain locations, and if you see the dots clustering in a certain area, you know that something is happening there. So, that's another very common use of points. The second one is bars. Bars are also very common, as you might have noticed, already in the course I've shown you a lot of examples with bar charts. So bars. Bars and bar charts are extremely versatile. So, the standard version is something like this, again and you have bars. So typically, in a bar chart as we have seen before, the x position is associated to some categories, or some ordinal values, and the length of the bar represents the value on the y axis. Bars sometimes are also visualized horizontally like this. There will be an horizontal version of a bar chart. So, that's the use of bars. The next one is lines. Lines are also very common and very versatile. Let me give you a couple of examples in which lines are used, but in very different ways. So, a very common one is the use of lines in a line chart. And typically to show something evolving over time. Right? That's also a type of chart that we've seen numerous times in the course so far. But lines are also used in the node-line diagrams, when we have a network. So, we have nodes. And nodes are connected by lines. And the goal of the lines here is to show that there is a relationship between the nodes that are connected by these lines. A similar one is also a tree structure like this one. Again we have nodes, and lines that are connecting the nodes. The last one is areas. So, this is a general term that covers a lot of different things. So, let me draw another example of a scatter plot where instead of using points, we have circles that can have different sizes. So, that will be an example of using symbols that have an area that is meaningful. But, you have other situations where areas are used. For example, again in maps. I think I've shown you before situations where there is a map with different counties or regions. So, again I'm not particularly good at drawing that, but let me show you an example. So there will be different regions in a map, and each of these one can be considered an area. Okay. And there are many other visualization methods that use areas. So, one that we didn't discuss yet in the course is a tree map, is a visualization that splits the screen into a number of areas to show hierarchical information. So, I'm not pretending to describe this in detail now, but I'm showing to you how this looks like. Okay. So, every rectangle here represents one element in the data. And it's another example of using areas as visual marks.