I have a black oxide bit and a titanium bit but do not understand what the difference, if any, is between them. Is it how long they last or how they cut the wood? Anything on this would be great!
Bits coated with black oxide should be cheaper than titanium ones. They have decent heat resistance. Most sites that talk about the breakdown between the types rate these for better water, rust and corrosion resistance.
Titanium is a little ambiguous as there are multiple coating that use titanium. For the most part though they should outlast black oxide bits and are better rated for heat resistance. so you should be able to run them faster for longer.
What does this mean for a woodworker?
Both bits are rated for more or less the same materials. It is true that titanium coated should outlast a black oxide coated bit. However, for a wood worker, they should both be just fine and provide the same results in relatively comparative times (This largely depends on each bits size and pitch as well as some other factors).