> As we turn to improving the performance of the actual initial JavaScript execution, however, we start to hit limitations when optimising our interpreter. V8’s interpreter is highly optimised and very fast, but interpreters have inherent overheads that we can’t get rid of; things like bytecode decoding overheads or dispatch overheads that are an intrinsic part of an interpreter’s functionality.

So when developers talk about a “compiled language” they really mean if the standard tooling supports a compiler; and if programs are generally distributed already-compiled.

There are implications (good and bad) to programs that are already compiled, versus a just-in-time compilation via a runtime engine; which is largely transparent to developers and end-users.