screen — pushed onto the back stack; back closes it;
tab — a bottom-bar root; opening it brings the tab's own stack to the
front (a fresh tab enters, a kept one resumes) and it has no origin, since
what is kept below it belongs to the tab, not to the edge that reached it;
innerTab — a top tab inside the screen on top (SERP Top → Accounts): it
replaces that screen's frame with the same chain length before, and back
closes it together with the screen it replaced (owner decision 2026-10-21);
item — an item of a list a host screen shows (defineScreenItem); never
a frame or a chain entry.
What a screen is to the app's navigation:
screen— pushed onto the back stack;backcloses it;tab— a bottom-bar root; opening it brings the tab's own stack to the front (a fresh tab enters, a kept one resumes) and it has no origin, since what is kept below it belongs to the tab, not to the edge that reached it;innerTab— a top tab inside the screen on top (SERP Top → Accounts): it replaces that screen's frame with the same chain length before, andbackcloses it together with the screen it replaced (owner decision 2026-10-21);item— an item of a list a host screen shows (defineScreenItem); never a frame or a chain entry.