In a manner similar to bacon, cured seafood is usually smoked in some way, and it is typically brined before the smoking step.
Gravlax, on the other hand, is cured without being smoked at all, making it almost ridiculously effortless and a great way to get started with curing. Salmon fillets are hit with a splash of booze, coated with sugar and salt, and blanketed with a thick layer of dill.
Then, press the salmon under a weight and refrigerate it for a few days, during which time it releases moisture and is cured and flavored by the salt (the sugar, dill, and liquor lend a hand, too).
Once a day, baste the salmon with the released liquid. Finally, on the last day, brush away the toppings to reveal the tender, compact fillet, ready for slicing and serving.