A phenotype is how the plant actually turn out. Like height, smell, color, taste, ect... You can kind of get an idea from the seed company but what you actually get is up to luck. That's why when you get a really good plant that grows just the way you like, you should clone it. That way you have an exact copy of that phenotype. You can crack 10 seeds from the plant ans get 10 very different plants from her. For example on some strains there is a 25% chance that you will get a strawberry phenotype. (sorry I cant remember the strain of my example) Hope this helps!