Speaking for Canada you would have "name"/ "street address"/ "town or city"/ "prov."/ "Canada"/ "Postal Code"
The postal code can be after the province also.
Pretty much the same as your address is.
In Canada and the US all the sorting is done by computer based on the ZIP (+4 please) or postal code.
In letters the computer will look for a TYPED ZIP/postal code in the last item in the address or the right of the 2nd last line (I do not trust the computer to do the 2nd one properly).
For handwritten letters or where the computer can not locate the ZIP/Postal code (code not the last line in the address or the right of the 2nd last line) the letter is rerouted to a postal clerk to type the postal code (delay 1 day?).
For letters without the postal code the letter is routed to another clerk who looks up the postal code based on the address and types it in (delay 1 week?).
The computer will then print a bar code on the letter in not so invisible ink.
For parcels the clerk at the Post Office will type in the ZIP/Postal Code and out pops a barcode sticker which he/she will attach to the parcel. The computer will then sort by that barcode sticker, not by the address you have written on the parcel.
For a ZIP+4, Canadian Postal Code the computer will sort all the way to the bag for the block & side of street or for an apartment building. For ZIP without the +4 the computer will send the item to the nearest Post Office or Sorting Center where the item is sorted by hand (delay 1 day?)
In the olden days writing the address the proper way allow the clerk at each sorting stage to find the information needed quickly so speeding delivery. Country, state, town, street, street#, suite# from bottom to top, right to left.
Today the address is for backup re-sorting if the computer or the postal clerks typing in the postal codes goofs.
I have sent myself letters by simply TYPING:
Apt#
Postal Code
and it arrived in my mailbox the next day.
Be friends with the post office computer, not with your English teacher who may have learned how to address letters before the post office discovered computers.
Many countries do not have computerized ZIP/Postal code systems. For those the addressing should be done the proper old fashioned way or as provided by the recipient.