Meguiar's 205 is a versatile tool that should be in every detailer's arsenal.  This product can be used in a variety of situations, and is suitable for use by hand, dual action polisher (random orbital), or by rotary.It should be noted that Meguiar's Ultimate Polish is based on the same technology and formulation as this product.  Ultimate Polish has more polishing oils, but less abrasives.  If your paint is already in great shape, Ultimate Polish would be the better product to use due to the higher oil content.  M205 has more cutting ability, and will therefore have more restorative power to your paint finish.  Unfortunately, M205 is also more expensive.M205 is a professional caliber Meguiar's product that is used to remove fine swirls or haze from paint.  M205 is very rich in polishing oils, and should be used as the final step before waxing in order to great a high reflection, high gloss shine on the paint.  This product features SMAT -- super micro abrasive technology.  This is a huge improvement over older diminishing abrasive polishes.SMAT technology involves the use of aluminum oxide particles in suspension that are extremely tiny, hence the term micro abrasive.  As you polish, these particles help strip off dead oxidized paint and boost the clarity of the finish.  Older diminishing abrasives products must be worked sufficiently to break down the abrasives into smaller and smaller particles until they are "all gone."  The problem with these types of products is that if they are not worked in sufficiently, they will create a haze on the paint or even instill swirls.SMAT technology polishes can be worked for any length of time, as the abrasives do not change or break down over time.  This makes this polish much more user friendly than older polishes.The proper use of 205 falls under two categories:1) Using as a follow up to a product like M105 (an extremely aggressive cutting compound).  M105 can sometimes leave hazing in the finish.  M205 on a polishing pad will clear this right up.2) Using less for the cutting power and more for the finishing characteristics of the product.  This would be done on a less aggressive (jeweling) pad and likely with less speed and pressure than as a follow up product.The M105/M205 product combo is probably the most well-respected on the market.  No detailer should be without this stuff.  If you are just starting out, take a look at Ultimate Polish.  Its' about half the price, and the higher oil content will make it easier to use.  Higher oil levels will allow the product to be worked onto the paint longer without drying out.