It is very difficult to compare both cardio and weight training in terms of which is better, as both forms of exercise have different benefits for the body! Cardio is short for cardiovascular exercise, and this is anything which gets your heart pumping faster such as running, elliptical machine or bike. The beauty of cardio is that is burns a lot of calories, and can be useful in the battle for weight loss when combined with a healthy diet.
Weight training, also known as resistance training is good for building up the strength in your muscles. There are loads of different weight training exercises you can do, from ones involving just your body weight (such as press ups and sit ups), to using dumbbells and kettle bells to train individual muscles. It is a good idea to combine weight training exercises with cardio in order to burn off fat and see faster results.