Raster Boolean overlay is another form of local raster operation. So let's have a look at how that works. You're probably familiar with Boolean operations in other contexts. Whether it's a vector overlay or even just doing some kind of a search where it's this and that this or that, those are Boolean operators. So here we have two different raster data sets. One is Soil Type and one is Rainfall and we can set up a Boolean operation where we're looking for the intersection in this case between areas where Soil equals 5 and Rainfall equals 20. So it's going to go through both of these data sets looking for the unique combinations of both of those if you think of it sort of like a Venn diagram with two sets. The result with a raster overlay is that you're going to get cells that are either 1s or 0s. It's essentially testing to see what's true or false. So the areas in red here that are 1s are the cells that match our criteria. So we have areas that are 5 and 20 and so that's true because both criteria have been met and so that's why we get a 1 there. Whereas, if we have a 10 that does not match that criteria so here we get a 0 because it's not part of the result that we're looking for. That's basically it. So let's see how this works in action. It is a very handy tool in the spatial analyst extension for ArcMap called the Raster Calculator. So this is set up to look kind of like a regular calculator and what we can do is in this case is notice that there are four operators that have these slightly unusual notations I suppose. The ampersand represents the intersection. That long straight line is union. The little hat is exclusive-OR, and the tilt is NOT. I'm sure there's a better name for that but I can't think of it right now. So those are the symbols that are used to set up these Boolean operations for raster data sets. So for example, if we wanted to find locations where we have an NDVI class of five, and if we have classes from 1-5 where five is the most vegetation. So that's the most vegetated areas, as well as areas that are designated as parks in terms of their land use that might be an interesting combination. So where are there areas that are parks, that are also heavily vegetated. So we could use a Boolean operator to look at NDVI class 5 AND Parks. So if we put this into our raster calculator, you'll see here and I've got this, so it's a little easier for you to read, is NDVI five, class five and park rec. So that's the name of the two things here from there. We're using the AND as the operator between them to look for the intersection of these two sets. So this is the result that we get. These are the areas that meet both criteria. You'll notice that we have in our legend just areas that have a value of 1, and if we open the attribute table for that same thing here, there's only cells with values of 1 because that's all that's kept in the result of a Boolean operation in raster is areas that meet our criteria. So for example here, this is High Park. So those are the cells that are both parks and rec and NDVI five. Here we have it for the entire city. So this is the result of our operation. That's all there is to it. I just wanted to make sure that was clear to you, is that you can use the raster calculator to perform Boolean operations. You can do intersections, unions, and so on. So it's a very handy tool to have at your disposal.