An Albedo Map is basically an Image texture without any shadows or highlights.
Take the image below as an example. On the left, we have a picture of a brick wall with shadows and highlights and on the right, these shadows and highlights are missing. The image on the right is an Albedo Map.
Side by side comparison of a regular Photo and an Albedo Map.
Ambient occlusion is a shading and rendering technique used to calculate how exposed each point in a scene is to ambient lighting. For example, the interior of a tube is typically more occluded (and hence darker) than the exposed outer surfaces, and becomes darker the deeper inside the tube one goes.