As nouns the difference between class and layer
is that
class is (countable) a group, collection, category or set sharing characteristics or attributes while
layer is a single thickness of some material covering a surface.
As verbs the difference between class and layer
is that
class is to assign to a class; to classify while
layer is (ambitransitive) to cut or divide (something) into layers.
As an adjective class
is (irish|british|slang) great; fabulous.