Each platform has its native bindings. For graphics, you write CSS and HTML canvas API as well as JSX, it renders to native components and their alignments, the canvas API is converted to native surfaces, whatever the platform uses.

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zerr 2 hours ago | parent [-]

I mean, is it OpenGL, Vulkan, Metal? etc...

	▲	dashersw 5 minutes ago \| parent [-]
		It defers to platform defaults, Android compositor, UIKit/AppKit native views or CoreGraphics for the canvas on Apple platforms, GDI/GDI+ on Windows, whatever SDL2 chooses on Linux. If you have a Three.js app, it uses Metal on iOS and macOS, Direct3D 11 (open) and 12 (commercial license) on Windows and XBox.