In the olden days of stage musicals, before the use of the microphones, most female opera singers used the belt technique so their voice can still be heard on top of the full orchestra accompaniment.
The essence of "belting," as it is commonly called, is the thick vocal folds that are working strongly, while the throat is held open; i.e. no forcing, constricting or yelling.
This technique must be used with extreme caution because it can sound irritating and boring at times.
In this lesson, I will teach you the belting technique in your own way of singing but will not highly recommend it if it doesn't suit your voice.