Keeping with the crafting theme.
Nearly everything in the galaxy can be crafted with the exception of elements and compounds. Is it realistic to find steel, a metal alloy, on a planet? No, but it makes better game play than to expect players to use schematics to craft steel themselves.
This amounts to four types of schematics that exist in the game.
- reverse engineered schematics
Nearly everything in the galaxy can be reverse engineered to create a schematic capable of producing the object you have on hand. When a schematic is produced in this manner, the understanding of the best resource attributes is not always possible to view. Depending on your skill level for reverse engineering your schematic will range from only knowing the necessary elements to make that object to knowing the amounts and best attributes to make the object exactly as you found it.
- general use schematics
Since nearly everything can be crafted, many schematics are learned while advancing in the crafting professions. Every player starts with a handful of known schematics.
- looted schematics
These are typically rare. Depending on the quality of the loot, the schematics will give more or less information about the best elements to use. Some very rare schematics may also only allow a single use and create an object that not even the most skilled reverse engineer can figure out.
- element refining schematics
Elements can be refined to make some attributes better. There are always adverse effects in the refining process. For example, removing magnetic properties from steel may also weaken it making the tensile strength properties also go down. Refining is handled by very skilled miners, a lot can be done by trial and error but it can be helpful to create schematics so that the process can be repeated as well as scaled up. So it is possible to create massive refining facilities able to produce similar elements and compounds so that crafters are able to mass produce low, mid or even high quality products.
What can get tricky is that many schematics won't tell you just how much of an element to use. So say you have a schematic to build an engine. It requires steel. If you put in 500 units, it will make the engine. But then you realize that after some experimenting, if you put 5000 units of steel the engine has much better stats. So then you increase to 10,000 units and think you've just created the be-all and end-all of engines. Trouble is that the mass of the engine is now well above 40 tons and most ship manuals suggest that you never exceed 3 tons for this type of engine. So you have an awesome engine that if you put it on a space ship, the ship won't lift off the ground.
But schematics don't all have to be that complicated. There are different levels of crafting. But if you want to build the best components in the galaxy you will have to learn the complexities of schematics. If you just want the ability to craft mediocre stuff, then there are in game crafting units that will dub things down a bit.
So that's schematics in a nutshell. They are actually more complex than that but that will require playing the game to really see just how extreme crafting can be, if you want it to be.