A ketogenic diet is literally a ketone producing diet. This is a very low carbohydrate diet typically less than 50 grams of carbs per day and high in fat about 60% of daily calories. When there is very little carbohydrates available we use lipids as a main energy source which we break down into ketones.
There are many approaches to Ketogenic diets in terms of macronutrient ratio and even food types. There is classic, cyclical and targeted ketogenic diets. There is no best options in general if the diet is hypo caloric and sustainable that is what the best pick for you.