All skills provide a number of basic capabilities on their subject. First, a skill provides knowledge related to the field. If you have high Athletics, you also know about the rules of many different sports by default . Second, a skill grants awareness about the subject. You find it easy to notice that someone is packing if you have a high Firearms skill. Third, a skill gives you aptitude. The ability to get something done in a good way. With high Research, not only you can dig up an obscure fact but also present that fact in a comprehensible way. Next, a skill allows appraisal. The ability to evaluate. You would need a decent level of Close Combat to be able to identify a Masamune sword. Last but not least, a skill gives you renown. You are known for being good in that field. Everybody knows you in the aviation industry if you have Piloting as your apex skill.