Tinder & Kindling
Tinder is mostly dry and very easy to light. There are many kinds of tinder to look for such as silver birch bark, the shredded inner bark of chestnut, cedar, dead grass, sawdust, downy flower heads (which look like cotton) magnesium powder and so on. Essentially what you are looking for is something that will ignite with very little heat from either a spark from your fire steel or ferro rod, a match, or a lighter. You may have some prepared tinder with you, like cotton wool in wax, fire plugs or a store brought fire lighter.
Kindling is also dry and very combustible. Once your tinder is alight, you will start to add this. Use the thinnest first, then build up from there. It's always best to have your tinder and kindling ready, you don't want to have to get some more. Kindling is a slightly larger than your tinder, small twigs, wood shavings, cardboard, fatwood. These items are slowly stacked on top of your ignited tinder so as not to smother the flame. Put it on slowly and gradually build it up. Then you will be ready to add on your fuel.