Lasers produce a single wavelength of light (pure light consists of a single color and shape) that has a very concentrated beam and a specific target (melanin in the hair follicle).
IPLs are not lasers. These machines produce a wide range of wavelengths  and cannot be focused into a concentrated beam. Because a number of different wavelengths are scattered at different depths, only some of them will be effective in reducing hair growth. With IPL technology, light penetration is very superficial and thick hairs cannot be treated effectively.
On the other hand, the laser works with energy that is many times stronger than that of IPL and respectively achieves better results. Because the heat is absorbed by the follicle and not the skin, there is a reduced risk of burning. This makes laser one of the safest hair removal options worldwide.

It is strictly individual for each person, but you will have a great result at the very first procedure. For women, it is standard from 5 to 7 procedures, and for men from 6 to 8 procedures for complete hair removal.

It is strongly recommended to shave the area to be treated, because any hair that is above the surface of the skin will block the laser from reaching the hair follicle, which is necessary for laser hair removal to be maximally effective.