What are 'syn bin' and 'syn bags'?

[PlayingHouse]

I have heard these mentioned online and briefly in group but have no idea what they are.

Do I need them in my life?

I make syn bags that contain 10 syns per bag. for instance, milky way 5, pink n white 2/3 (can't remember) and minion crisps, then once the bag is empty that's all that I can have

Oh OK, it's to stop people going over their syns?

I think so, if you absolutely know how many syns are.per bag. Then you won't be tempted to look elsewhere.