What do the different numbers on plastic items stand for?

Almost all plastic items are marked with a number inside the symbol of three arrows chasing each other. These are known as Plastic Recycling Codes. Plastic recycling codes help identify the constituent raw materials of a particular item or product which helps categorize plastics into 7 major categories.
These different numbers or plastic recycling codes on the plastic items, help recyclers quickly learn about the plastics biodegradability or how likely is the plastic to leech.
You can learn more about this at : https://greensutra.in/news/plastic-recycling-codes/