Some time ago, an online poll by 35,000 people held by CNN International chose Rendang Padang as the number one dish of their 'World’s 50 Most Delicious Foods' list.
Broadly speaking, rendang is curry beef which is cooked until caramelized. All the liquid has evaporated, staying concentrated fragrant spices. While the meat has become tender though still textured. Therefore I strongly agree with the nomenclature in English - caramelized beef curry - by William W. Wongso. That is, if it is not caramelized - such as: kalio - it's not enough to be called rendang.
Rendang is not always made from beef. We also know chicken rendang from Kapau cuisine, or when you travel to Payakumbuh, you will find eggs rendang are sold as souvenirs.
Delicious rendang is always resulted of the use of proper seasoning and proper cooking process. Traditionally, rendang cooked with firewood, the aim is to cook it with small fire, and get the smoke flavor. When the cooking is done by a modern gas stove, slow cooking principles must still be done so that caramelization occurs without making it charred and shrunken hard.