You supply the
action attribute serves a role of navigation URL, a.k.a. "plan to navigate".
target attribute defines where to load that response returned by the server.
So yes, that is "an intrinsic property of how HTML form elements work".
Algorithm of handling form submission is defined in HTML4 and HTML5 forms specifications.
Submitting the form is essentially an ordinary URL navigation (by
<a href> elements) but with automatic parameters gathering that go either into final navigation URL as parameters (
<form method="get"> ) or as request body parameters (
<form method="post"> )