USB ports in Linux system

When I check "/sys/kernel/debug/usb/devices" in a Linux system, I could see that two devices are on the same port(T: line in below output). Also the port numbers in "D:" line is different.

Device1:

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 8B:  Alloc=  0/800 us ( 0%), #Int=  2, #Iso=  0D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1P:  Vendor=1d6b ProdID=0002 Rev= 3.10S:  Manufacturer=Linux 3.12 ehci_hcdS:  Product=EHCI Host ControllerS:  SerialNumber=0000:00:14.0C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hubE:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms

Device2:

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480  MxCh= 4D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1P:  Vendor=8087 ProdID=07e6 Rev= 0.17C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hubE:  Ad=81(I) Atr=03(Int.) MxPS=   1 Ivl=256ms

Is there something like physical USB port and logical USB port in Linux USB subsystem.If so, then can you help in understanding physical and logical USB ports.