hardwood or softwood?
Softwood
Softwoods tend to burn hotter and faster, they can be easier to light, however tend to have lesser coaling qualities giving a finer ash and hence not as long lasting.
Hardwood
Hardwoods are great for a longer lasting heat and flame; they tend to produce hotter coals, providing more radiant heat for a longer time making them more suitable for overnight burning in the stove.