Most skills are very broad categories. It may suit your character to excel in one or more area of that skill.

For Example: A doctor would be a Natural Studies expert who specializes in medicine. An assassin would be a Natural Studies expert who specializes in poisons. A zookeeper would be a Natural Studies expert who specializes in wild animals.

Taking a specialization costs 1 additional XP. If you are using your skill in a situation appropriate for your specialization, you will have a slightly greater chance of success. Mechanically speaking, you will be granted an additional edge one degree less than your skill. Being specialized is never a penalty.

Taking a specialization for a skill at level 1 will not give you an edge. It is merely for flavour purposes.

Specializations are part of training your skills. The 'Max Specs' represents how many specializations you will need to get a broad understanding of the skill. If you have this many specializations, you may trade them in to increase you skill level. You will lose the specializations, but have a higher skill level.

For Example: Godam is an expert architect, at Level 2. He is specialized in Bridge construction, Irrigation Systems and Storm Defenses. After some hard study, he has a broad knowledge in Anti-Piracy measures. With all this special knowledge, he is practically a master architect. He turnsheets to trade in his 4 specializations, and become an unspecialized level 3 Architect.

Therefore, even level 1 specializations have value.