What is a logical buffer in the context of OpenGL?

I was reading this article on framebuffers and it mentions: "The framebuffer consists of a set of logical buffers: color, depth, accumulation, and stencil 开发者_如何学Pythonbuffers."

What does the article mean by "logical buffers". In particular I'm confused by the use of "logical". As opposed to what other type of buffer?

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I think it means that physically, there's one big buffer (framebuffer), but it's logically divided into different parts storing different types of data.

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The logical buffer is a data surface that can be rendered to. It's an abstraction between Texture and Renderbuffer.