Here are the data structures with brief descriptions:

Clibusb_bos_descriptor	A structure representing the Binary Device Object Store (BOS) descriptor
Clibusb_bos_dev_capability_descriptor	A generic representation of a BOS Device Capability descriptor
Clibusb_config_descriptor	A structure representing the standard USB configuration descriptor
Clibusb_container_id_descriptor	A structure representing the Container ID descriptor
Clibusb_control_setup	Setup packet for control transfers
Clibusb_device_descriptor	A structure representing the standard USB device descriptor
Clibusb_endpoint_descriptor	A structure representing the standard USB endpoint descriptor
Clibusb_init_option	Structure used for setting options through libusb_init_context
Clibusb_interface	A collection of alternate settings for a particular USB interface
Clibusb_interface_association_descriptor	A structure representing the standard USB interface association descriptor
Clibusb_interface_association_descriptor_array	Structure containing an array of 0 or more interface association descriptors
Clibusb_interface_descriptor	A structure representing the standard USB interface descriptor
Clibusb_iso_packet_descriptor	Isochronous packet descriptor
Clibusb_platform_descriptor	A structure representing a Platform descriptor
Clibusb_pollfd	File descriptor for polling
Clibusb_ss_endpoint_companion_descriptor	A structure representing the superspeed endpoint companion descriptor
Clibusb_ss_usb_device_capability_descriptor	A structure representing the SuperSpeed USB Device Capability descriptor This descriptor is documented in section 9.6.2.2 of the USB 3.0 specification
Clibusb_transfer	The generic USB transfer structure
Clibusb_usb_2_0_extension_descriptor	A structure representing the USB 2.0 Extension descriptor This descriptor is documented in section 9.6.2.1 of the USB 3.0 specification
Clibusb_version	Structure providing the version of the libusb runtime