There are two general types. The more standard kind is very easy to strike and throws a shower of sparks about a quarter to half inch from the rod.

Then there's a softer type that's sometimes called misch metal, and it throws off fairly large globs of red hot metal that can travel a couple feet before they burn out. But they require a sharper striker and more force to work well.

Which is better really depends on your technique. Regular ferro rods are more controllable so likely preferable for a beginner. Misch metal is a bit more difficult to strike and requires a little more practice to aim where the fire is going.