Cutting is a collection of processes wherein material is brought to a specified geometry by removing excess material using various kinds of tooling to leave a finished part that meets specifications.  The net result of cutting is two products, the waste or excess material, and the finished part.  In woodworking, the waste would be sawdust and excess wood.  In cutting metals the waste is chips or swarf and excess metal.
Cutting processes fall into one of three major categories:
* Chip producing processes most commonly known as machining
* Burning, a set of processes wherein the metal is cut by oxidizing a kerf to separate pieces of metal 
* Miscellaneous specialty process, not falling easily into either of the above categories
Drilling a hole in a metal part is the most common example of a chip producing process.  Using an oxy-fuel cutting torch to separate a plate of steel into smaller pieces is an example of burning. Chemical milling is an example of a specialty process that removes excess material by the use of etching chemicals and masking chemicals.
There are many technologies available to cut metal, including: 
*Manual technologies: saw, chisel, shear or snips
*Machine technologies: turning, milling, drilling, grinding, sawing
*Welding/burning technologies: burning by laser, oxy-fuel burning, and plasma
*Erosion technologies: by water jet, electric discharge, or abrasive flow machining.
*Chemical technologies: Photochemical machining
Cutting fluid or coolant is used where there is significant friction and heat at the cutting interface between a cutter such as a drill or an end mill and the workpiece.  Coolant is generally introduced by a spray across the face of the tool and workpiece to decrease friction and temperature at the cutting tool/workpiece interface to prevent excessive tool wear. In practice there are many methods of delivering coolant.