What are differents between drawLine directly and drawLine wrapped in drawIntoCanvas in Jetpack Compose?

I'm learning Jetpack Compose Canvas.

I met the two different Code both Code A and Code B.

Code A invoke drawLine directly, and Code B invoke drawLine which is wrapped in drawIntoCanvas.

1: What are differents between Code A and Code B ?

2: Which one is the better between Code A and Code B ?

Code A

@Composable
fun setCanvas() {
    Canvas(
        modifier = Modifier
            .fillMaxSize()
    ) {
        val canvasWidth = size.width
        val canvasHeight = size.height

        drawLine(
            start = Offset(x = 0f, y = canvasHeight),
            end = Offset(x = canvasWidth, y = 0f),
            color = Color.Blue      
        )
    }

}

Code B

@Composable
fun setCanvas() {
    val linePaint = Paint()
    linePaint.isAntiAlias = true
    linePaint.style = PaintingStyle.Stroke
    linePaint.color = Color.Blue

    Canvas(
        modifier = Modifier
            .fillMaxSize()
    ) {
        val canvasWidth = size.width
        val canvasHeight = size.height

        drawIntoCanvas {
            it.drawLine(
               Offset(x = 0f, y = canvasHeight),
               Offset(x = canvasWidth, y = 0f),
               linePaint
            )
        }

    }

}