The term "tuck", meaning food, is slang and probably originates from such phrases as "to tuck into a meal". It is also closely related to the word "tucker", also meaning food.
In Australia, the term tuckshop is interchangeable with the word canteen. The tuckshop is a shop in a school where the food is preapared and sold to school kids.
A tuckshop also sells confectionery finger-food, such as sweets, crisps, water, juice, fizzy drinks and so on. In recent years, there have been moves to change to a wider variety of healthier food.
In primary schools, the tuckshop opens twice a day: at recess (first break) and lunch (second break)
The tuckshop is mainly staffed by parents or volunteers from the community. In recent years, because of shortage of volunteers, some tuckshops are run by paid staff.
Parents write students orders on a brown paper bag, enclose the equivalent amount of money and send it with the kids to the school. Usually the kids drop these brown bags in a special box near the tuckshop or in the school office.
In recent years, due to the popularity of doing things over the Internet, a parent introduced online ordering for tuckshops. The way it works:
These systems are getting more popular. Schools start switching to the online ordering service which save time and reduce wastage.