Albedo

Albedo is a big fancy word that people use to talk about how bright or dark different things are. Imagine you're outside on a really sunny day and you're wearing a white shirt. Your shirt is reflecting a lot of the sunlight, so it looks really bright. But if you were wearing a black shirt, it would absorb a lot of the sunlight, so it would look really dark.

Now take all the things on the earth's surface like mountains, trees, and oceans, for example. They all reflect different amounts of sunlight. Some things, like snow and ice, reflect a lot of sunlight back into space (just like your white shirt!). This means that they have a high albedo. Other things, like forests and oceans, absorb more sunlight, so they have a lower albedo.

Albedo is really important because it affects how much heat the earth absorbs from the sun. The more sunlight that's reflected back into space, the less heat is absorbed by the earth. This is one of the reasons why the polar ice caps are so important - they have a really high albedo, so they reflect a lot of sunlight back into space and help to keep the earth from getting too warm.

So in short, albedo is just a way of talking about how bright or dark different things are, and how much they reflect or absorb sunlight.