In USA and Canada they are called Panties,in the UK and Commonwealth they are called knickers.They are being made from fabrics such as cotton,lace,satin and silk.
The different types of panties consist of:
Briefs-rise to the waist or just below the naval with full rear coverage.
Hipster-similar to briefs but are worn lower with waisrband around hips.
Thongs-rear coverage is not full.
G-strings-is a thong with no rear coverage.
Bikini-worn on the hips but sides are narrow.