It means that JS does not require the explicit declaration of the variables before they’re used. Here is a quick example that compares Java, a statically typed language, vs.
Which programming languages are called dynamically typed?
What is the difference between statically and dynamically typing?
First, dynamically-typed languages perform type checking at runtime, while statically typed languages perform type checking at compile time. … If a script written in a statically-typed language (such as Java) contains errors, it will fail to compile until the errors have been fixed.