Crafting is a game mechanic that allows players to combine items and components to create other items. Crafting any item takes time; items that are more expensive, larger or just more useful take more time to craft. Crafting more items at a time will also increase the time it takes to crate them.
When crafting is active, players are given the "Crafting" status and will move significantly slower during this and also lose the ability to sprint, making them much more vulnerable in open areas.
Some complex and useful items require standing near a workbench (thus giving the player the "Workbench 1" status) to be crafted, meaning that the player has to stay near a workbench and retain the status while such items are being crafted, as moving away from one will remove the Workbench 1 status and suddenly stop the crafting process. When you return to the workbench you will have to start over from the beginning.
In order to begin crafting, press the Inventory key (default: Tab) and look at the very top of your screen for the "crafting" tab. Click on the crafting tab to open the crafting menu. Select an item from the list and use the + or - keys to change the quantity to be crafted. You can hold the control key when clicking the + in the Crafting Menu to automatically set the amount to be crafted to the maximum amount you have components for.
Click Craft to begin crafting the item(s).
Players can stop active crafting at any time before it finishes by simply clicking a "cancel" button.