But in modern terms, mostly due to some people refering to the commercially made flint Ferrocium Rod as a "fire steel" (which it is not), tinder now includes kindling. As you can imagine, being now no distinction between kindling and tinder, Pilgrims are getting confused when they are unable to catch a spark on kindling when they have just read that you can.
So my purpose here is to try and make it a little more clear and understandable. Firstly whenever you read the term "fire steel", take the time to ask the person if they are using a ferrocium rod. If they are, then you can ignore most of what they are talking about because it will have no bearing on YOUR use of a REAL flint and steel. Below are some examples of Kindling.
Top is some sisal rope strands, and below that the outer bark of the Stringybark tree.
A disused birds nest mostly made of dried grasses. In this form such kindling is often called a "tinder nest", which again can be confusing. This is kindling, not tinder.
Dried leaves from trees.
To the right in this basket are the dried stalks of the Jerusalem Artichoke plant, and to the left Mountain Gum bark. Sizes of kindling going up from this would be twigs and sticks of various sizes.