core::ivk::framebuffer_t::binding struct

describes a single binding point (can be many) in a framebuffer.

although most framebuffers are fairly simplistic, you might end up in scenarios where you will need to have multiple layers in your framebuffer. this is where bindings come in; even though most bindings will have 1 attachment, in a multi-layer scenario you can have many attachments, or have some indices all share the same attachment.