For most woodworkers, I'd say the analogy is closest to making "plugins" for existing tools. They require a little knowledge (which easily obtained on YouTube),

For most woodworkers, I'd say the analogy is closest to making "plugins" for existing tools. They require a little knowledge (which easily obtained on YouTube), and can greatly increase your ability to use the base tool. One example is a table saw sled, which helps you make clean, repeatable, 90º cuts. It's one of the most useful "plugins" you can have for your table saw, and relatively easy to make. Making the actual table saw, on the other hand, would be expensive and very difficult, and would require knowledge of many fields (metal working, electrical systems, etc.).