HelloPhysics tutorial texture question

In the HelloPhysics tutorial, the texture is load using TextureKey

[java]
TextureKey key2 = new TextureKey(“Textures/Terrain/Rock/Rock.PNG”);
key2.setGenerateMips(true);
Texture tex2 = assetManager.loadTexture(key2);
[/java]

But in HelloMaterial, the texture is load using Texture

[java]
Texture cube1Tex = assetManager.loadTexture(“Interface/Logo/Monkey.jpg”);
cube1Mat.setTexture(“ColorMap”, cube1Tex);
[/java]

So what is the different between TextureKey and Texture? In what circumstance using TextureKey and Texture?

As you see from the code you posted, when you want to set extended asset properties as in this example the mipmap generation you can use the AssetKey for that.