is a sealed class an abstract class?

not necessary, it may be abstract

in bytecode

It's by definition : a

sealed class

is a special kind of

abstract class

with a restricted inheritance hierarchy.

Yes

do we have like commonly-accepted terms to refer to both a

sealed class

declaration and classes that inherit from them?

I'm personally just call it sealed class

but then what do you call members of a sealed class?

They are simply a class