Hard ground comes in a wax ball. Dab it over a clean and heated plate and use a brayer to roll it out until it is evenly distributed. Now you can use a sharp tool, called an etching needle, to open lines in the ground. The marks you make will be bitten when you submerge the plate in a bath of acid diluted by water. Hard ground lines are usually wiry and blunt at the ends.
Soft ground wax is soft; it generally comes in a small jar. The lines in the finished print look like crayon or pencil lines. Soft ground, like hard ground, is rolled onto a plate, but normally you wouldn’t draw directly in the soft ground. Instead, lay a sheet of paper over it and draw with a pencil on that, pressing the paper into the wax as you work. When you peel up the paper your drawing in the wax has the texture of the paper you were pressing into it. After you have etched and printed the plate, your drawing will look very much like a pencil drawing. Another way of using soft ground is to press something textured into it: a leaf, or piece of cloth, or anything flexible. After you pull up the material, its image will etch nicely.