A schematic is a simplified diagram of a complex object that acts as a guide to building that object. In Astroneer, schematics are represented by pale blue transparent versions of objects than can be made by players at either the Backpack or any form of crafting Module. Schematics are also used to represent materials or tools required for activating most modules. Schematics are also commonly known as blueprints or recipes.
In Astroneer, players can see which schematics they have by using the forward and back arrows while the backpack is open or while standing at a crafting module like the Printer. As you "page through" the list, a visual representation of each schematic and its ingredients will appear. For example, you may see the schematic for a Solar Panel, Wind Turbine, or Storage Unit at a printer, or at the Vehicle Bay some basic vehicles, like the Rover. Assuming the required resources aren't attached to the platform the module is on, holograms which look like schematics will appear outlining what the crafting schematic requires.
Some schematics must be Researched from Artifacts. For example, the Filter schematic must be researched before it appears in the Backpack's options and more complex vehicles like the Truck and Spaceship must be discovered before they appear in the Vehicle Bay.