Avoid silicone-based products as they are not beneficial to paint and can cause problems down the road. Ask any professional car painter their thoughts on silicone products, and you will usually get a 30-minute tirade. A glaze usually denotes a superfine friction type of cleaning agent, usually with essential emollients and lubricating oils and may even contain some mild chemical cleaners. Glazes will usually remove mild swirl marks, scratches, refresh the paint with oils and smooth out the finish. A polish is normally a non-abrasive product based on a nutrient oil matrix and may or may not have a chemical cleaner as part of the package.
Most polishes use fillers to help cover swirl marks.
This should be used only if the paint is in serious trouble and all else has failed. This type of product must be used with lots of lubricant. The technique of using a clay is a learned skill. Use too little lubricant, or get contaminants in the clay, and you have moved into scratch city. This is one product that is the fast lane to trouble if not used with extreme care.