Elements

Click, Wait, Scroll and Zoom take an element:

Write Means
"Save" The element whose title, description or value is exactly Save. Quoted is always a label.
Save The same, unquoted, for a single word.
#save-button The element whose accessibility identifier is save-button.
@120,80 A point, in points from the window's top left. A last resort: it breaks when the layout moves.

In an app, reel searches the app's windows breadth first, so sheets and popovers count, and takes the shallowest match. The element must be on a screen. Click waits for it for up to WaitTimeout (10 seconds unless set).

Identifiers are the sturdiest: a label changes with the language and the copy. In SwiftUI, give a view one with .accessibilityIdentifier("play").

On a page, an element is found by JavaScript in the page:

Write Means
"Sign in" An element whose accessible name, placeholder, title, alt text, button value or text is exactly Sign in. Controls come before other elements, then the smallest.
#email The element with that id, or that data-testid.
css:.submit The first visible match of a CSS selector. Quote it after the colon when it has spaces: css:"form button".

A click scrolls its element into the middle of the page first.

Wait [play] is not an element: it waits for narration to reach a [play] marker. See Narration.