The papaya is distinctive for the myriad, small, dark seeds (which look a bit like rabbit droppings) that fill the large cavity of the fruit.
It can be eaten unripe, when its firm texture and sharp, acidic flavour mean it's usually treated more like a vegetable (and is used in salads, for instance), and when the flesh is soft, sweet and ripe. The colour of the skin isn't always an indication of ripeness. The best way to tell if a papaya is ripe is by sniffing it for its strong, almost unpleasant, fragrance, and pressing on it - it should yield to gentle pressure.
It's an easy fruit to prepare: just cut it in half lengthwise, remove the seeds and fibres from the cavity, then scoop or slice the flesh from the thin, soft skin.
There are many types of papaya. Skin colours range from pale yellow streaked with green to deep orange while the flesh of the ripe fruit can be anywhere from pale peach-coloured to orangey-red. There's a wide range of sizes, too, although even the smaller types (about 12cm) make a fairly substantial serving.
Papain is an enzyme present in papaya that is used in marinades to tenderise tough meats. It's also said to have health benefits, including reducing inflammation and helping digestion.
In Thai cuisine, green papaya (the 'green' in this case not necessarily pertaining to the colour, but instead meaning unripe) is used to make a delicious, refreshing salad. The papaya flesh is shredded, then mixed with fish sauce, lime juice, a little sugar, garlic, chillies and other ingredients such as shellfish.