What really is a function expression? [duplicate]

Can someone explain me please if a function expression involves the function value along the variable in where it’s stored or is really only the function value?, so i always see that the “function expression” term points to this whole snippet:

const funcExp = function(){console.log("Hello World!")};

But i was wondering.. then what about this:

function(){console.log("Hello World!")}

if you ask me i would say that the function expression is only the function value itself, which basically would be a pure anonymous function, no? i could be wrong but.. do you really don’t think that would be strange to call this an anonymous function?:

const funcExp = function(){console.log("Hello World!")};

i mean in some way already has a name, not directly as part of the function value, but as part of the variable in where its stored, so i don’t know i just want to know what really is a function expression, the whole variable creation initialized with a function value or only that function value, if the first turns to be true then how do we call this type of function values function(){console.log("Hello World!")}? function expression also?; thanks.