Does HEAP mean the same thing with a table that has Non-Clustered index?

In terms of SQL terminology, does HEAP stands for a table that has Non-Clustered index?

Or there is a nuance or it has completely a different meaning?

Answer

A heap can have either no index at all or a non-clustered index. But a clustered table can also have non-clustered indexs on top so –

does HEAP stands for a table that has Non-Clustered index?

is not a great definition as a table with a non-clustered index could be either a clustered table or a heap.