How to overlay images

I know I could overlay bands before with layer manager. I create a k means classification and want to overlay it on the original image but I can not do this. Why not? I am using snap 2.0 on windows 10.

You can still do that, but first would need to stack the different products SAR image and classification results into a unique product. Then you can proceed as previously using the layer manager.

Hello Elena,
This is a known problem ( see SNAP-290). The check if two products are compatible is to restrictive here.
To overcome this you can collocate both products, as mfoumelis already said, or you can make a copy of the ‘class_indices’ band. The draw back of the latter approach is that you loose the colors.

Thank you

The toolbox is a really great tool.

Hi, I’m a beginner, could you please tell me how to overlay step by step? Thank you very much

Have a look at the Layer Manager.
There are also several tutorials for beginners. Give them a try.