These are the building blocks of a character. Skills are broken down into multiple categories based on their uses and the like but they all serve the same thing: to represent in-game ability to perform tasks. Most skills exist to aid a character in the adventuring aspect of the game and allow them to do tasks that
are typically not easily doable in the real world, but others are more mundane things that in the real world some people are versed in but others are not. Because skills are required to perform tasks, from advanced to mundane, it presents a problem in some senses when it comes down to actual physical abilities of players. If a skill is specifically written out for something then it is required to perform the task at Xadune. Semaphore, for example, is something you as a player might know in the real world; however, since there is a specific skill for this, unless you have that skill your character has no idea what it is or how to perform it. Some mundane skills not specified in the game system are allowed to be used if the player knows it on an out-of-play level, but if another player has a generalized skill that covers said task, like Craft Skill: Glassblowing, then the person with the actual skill in-game will produce better results. Final line: having the skill in-play will yield you better results.