The 80th anniversary is called the OAK anniversary. The traditional gifts associated are made out of oak. this can be a chair, chest, picture frame, or anything else.
Oak
Oak
platinum
Your 80th birthday is commonly referred to as your "octogenarian" birthday.
orange
A 90th birthday anniversary is commonly referred to as a "90th birthday" or a "90th birthday celebration." Some people may also call it a "ninetieth birthday" or a "90th birthday milestone."
diamond jubilee
Platinum year
"Happy 80th birthday!" in English is Auguri di buon ottantesimo compleanno! in Italian.
It's the Ruby Anniversary
a scratchbook of all the flashbacks
It is the Diamond Anniversary. This dates to the Diamond Jubilee of Queen Victoria (1897). 25 = silver 50 = golden 60 = diamond (originally 75th) 70 = platinum (UK - it is 20th in the US)
There is no difference, but birthday would definitely be the more widely accepted label. The word "birthday" itself is elegant - it accurately gets the point across with four less syllables than birth anniversary.
12p
The phrase for welcoming all for grandma's 80th Birthday in Malayalam is "അമ്മമ്മയുടെ 80-ാം പിറന്നാള്ക്കായി എല്ലാവരെയും സ്വാഗതം ചെയ്യുക" (ammammayude 80-aam pirannalukkayi ellavarum swagatham cheyyuka).