Crafting is the ability to create items using more basic ones. In Junk Jack X, crafting is used to craft better items in a crafting grid. If you don't know how to craft things in a crafting grid, there is an option in the Options Menu to enable Simple Craft.
 Simple Craft
Simple craft is an option to use the Craft Book as a "Crafting Grid". This option is automatically activated at the start of the game. It's recommended for beginners to use this option. You can turn it off in the "Gameplay" option section. During simple craft, you will not need to arrange the items. Instead, you will have to gather all of the necessary item to craft said item. When you make items, they will take time depending on the item.