Corn syrup is a glucose syrup derived from corn with some additives. Karo Light Corn Syrup is the most popular brand and has according to the manufacturer ‘is a mixture of corn syrup and high-fructose corn syrup , flavoured with salt and vanilla’. Also available as Dark Syrup. Corn syrup is used to help prevent the crystallisation of sugar in confectionery/sugar work, in frostings & some desserts.
Consider substituting for glucose syrup if unobtainable.
Availability in Australia
Difficult, some supermarkets do carry it, otherwise you will have to hunt it out at delicatessens & speciality grocers.