What is the function of a tool post of a lathe machine?

The tool post allows the user to control a cutting tool (such as a chisel) more accurately - to produce better results.

The tool post holds the lathe tools that will be required for each cutting operation required in that part of teh production process. Each post can hold up to four differing tolls - example. Facing tool, knurling tool, long reach internal cutter and then a parting tool. The tool post rides on the saddle on a horizontal plane and the in a cross feed. Most tool feeds can be set to automatic where cutting speed is set and the movement of the post on the saddle automated