Normal German Volume Training (GVT) involves doing 10 sets on two big, compound exercises, usually for 10 repetitions, followed by two other additional exercises for three sets, using 6-8 repetitions. In short, it basically works on the law of repeated effort to stimulate the body into growth.
It is very hard, stressful and tiring on the body! So you must have the conditioning, health and vitality to do it.
Read more on what German Volume Training is at Charles Poliquin’s website. (According to others, Charles Poliquin is regarded as the number one strength coach in the world, maybe ever!)
For more advanced lifters (who have been training for a number of years) 10 repetitions does not load the muscles enough to elicit a response. 3-5 repetitions is more ideal. Again, you can read more on Advanced German Volume Training here with this Charles Poliquin article.
Enjoy the benefits of German Volume Training.