So, here we have the blue band, green band, red band and so on, and so, the spectral resolution or the definition of spectral resolution is the number and size of the wavelengths, are the intervals, are the bands that are used by a sensor or what it's sensitive to. So, if it has more bands, it has a higher spectral resolution. If it has fewer bands, it hasn't lower spectral resolution. But there's a relationship I want you to be aware of between spectral resolution and spatial resolution and all this really has to do is to think about the amount of just think of it as light that's being reflected off of a square of land on the ground. So, if we have a certain spectral resolution like this, we have six different bands, that say, they're fairly narrow bands and the spatial resolution of that would be 30 meters. There's a different type of sensor. This is for, let say, this is a Landsat seven or eight that are the same on both of them, they have one really wide band called the panchromatic band and it's just you know it's panchromatic because it's going across a lot of different colors at once and you can see that it's a much wider band than the other ones. So, why is it so much wider, what's the strategy, what's the thinking there. Will, like I said, the one on the top that's the, what we call the multi-spectral bands. So, blue, green, red, and so on, have a spatial resolution of 30 meters. The panchromatic band has a spatial resolution of 15 meters. So, the relationship I want you to see here is that if we have larger cells like 30 meters, then we have more light that will be reflected off of that area because it's a larger area and so our sensor is able to detect that, and so we can divide up the spectrum into these narrower bands and still be able to detect enough light that the sensor can record it. Now, what if we want to have a much smaller cell, a much higher spatial resolution? Well, that means that we have a much smaller square on the ground and that means that there'll be less light because it's a smaller square. So, if you have less light, the strategy that's used here is they actually use a much wider band of the spectrum in order to try and capture that light and be able to record it. So, we can either have a smaller cells with a wider band and lower spectral resolution where we can have larger cells with narrower bands and have more combinations. So, the nice thing is that we can actually have both. Is there's two different sensors on Landsat seven and eight, one is multi-spectral and so that's what you're seeing in the top here and one is panchromatic which is on the bottom and so there's ways of working with both of those, in order to be able to decide, sometimes you want more detail so, we want the panchromatic band, but sometimes we want to have more information based on blue band versus red band, green band and so on, and so then we can use the multi-spectral bands. So, I hope that's clear, I do think it's useful for you to know that because when you're out looking for data and you're comparing different types of images and sensors, you will notice that some of them have higher spatial resolution. Some of them are lower. Some of them are multi-spectral, some of them are panchromatic, and just think of them as different options that are available to you.