I bought several at a tool reseller and have used them but some of the conversations here have made me wonder.
The ones I have are spiral cutters and clearly sharp on the end. They plunge better than a drill bit and will cut sideways. Most of them have two flutes but one has three.
So, what makes them different from a router bit or a drill bit?
And, I see videos of CNC machines cutting bunches of parts out of plywood or MDF and they appear to get a lot more mileage out of a bit than I do. What are they using.