I can't understand what is

Semantics

from the documentation: for example here:

Box(LayoutHeight.Fill + LayoutFlexible(1f), gravity = ContentGravity.BottomStart) {
            val baselineOffset = with(DensityAmbient.current) { TitleBaselineOffset.toDp() }
            AlignmentLineOffset(alignmentLine = LastBaseline, after = baselineOffset) {
                Semantics(container = true) {
                    CurrentTextStyleProvider(value = MaterialTheme.typography().h6) {
                        Row {
                            title()
                        }
                    }
                }
            }
        }

Can you please explain what is

Semantics

?

semantics is a subsystem of compose UI that allows us to kind of “mark” parts of the tree with metadata. This can be used for a lot of things: Testing, Accessibility, Developer tooling, etc.

Thanks, Is there any example of it's usage at the moment or it's not completed yet and we're gonna see it in future?

its being used across the codebase. for instance, you can look at Toggleable, Button, Checkbox, Text, etc.