Argan oil is the oil extracted by the kernels of the argan tree (which grows in Morocco). There, it is used mostly for food and cooking. Here and in many other places in the world, it is most popular for beauty and cosmetic purposes. It is the fruit of the argan tree from which the kernel exists is small and kind of round. The shape is that of an oval. It has a thick skin and once peeled back, it has a thick fleshy pulp inside. If you peel off the pulp, you will find the nut, or the kernel, which is what argan oil is extracted from.
You will find that the fruit sometimes contains up to three kernels. Almost as much as 50% if the oil extracted comes from the kernel alone. You can get more depending on how you extract the oil form the kernel. The extraction method makes a difference. The most popular way seems to be to dry the kernel first in open air and then once it is dry, you remove the fleshy pulp form the kernels. Others just remove the flesh without drying it first and just peel it off use their hands or a tool. Then the kernel is extracted immediately. In morocco they like to use the flesh as feed for animals like goats, etc. They don't eat it themselves.
Once the kernel is extracted from the flesh, the next step is to crack the nut. They will then roast the kernel and allow it to cool down. After it has cooled down, the worker will grind the roasted nut and then press it using a special tool. Of course, this method is if you were planning to extract the oil for cooking. For argan oils used for cosmetic purposes, the nuts are not roasted and are just grounded and pressed.
It is then left to sit for a few weeks so that the solids will settle to the bottom. The oil is then filtered further to remove the solid particles.