How can we understand spectral clustering algorithm in a more generalized way? The research papers mention it in more mathematical form. What could be a layman's approach to understand it by overlooking mathematical equations?
A simple answer is that, spectral clustering is useful when features that represent different values/items are present in feature space in linearly mixed form (for example in spheres around one another). In such case, simple clustering will not help and you will need spectral clustering.