Who it's for
New lifters, anyone coming back after time off, and anyone who can only train three days a week. The reason it works for beginners is frequency: you practise the main lifts three times a week, and practice is what makes the weight go up early on.
The week
Alternate Workout A and Workout B on non-consecutive days: A, B, A one week, then B, A, B the next. Monday, Wednesday, Friday is the usual pattern.