What is the difference between a trademark and a service mark? How?

A trademark indicates that the company makes a particular item, such as shoes, manufacturing equipment, frozen green beans, etc.; a service mark indicates that the company provides a service, such as fixing shoes, installing equipment, delivering green beans. The circle R indicates that the mark has been registered with the U.S. Patent and Trademark Office. The letters TM indicates that the mark hasn't been registered but the company is using it as a trademark.

Trademarks are the "brand name" of goods - think Ford cars, Tide detergent, Coca-Cola soft drink, etc. When you see a trademark - you know the product comes from one source - it is not "generic." Service marks are the "brand name" given to services, for work done by service providers. The circle R symbol designates that the mark has been registered with the United States Patent and Trademark Office. It means that the mark has federal protection - and the federal courts are used to enforce the rights against infringers. If the mark is not federally registered, you should designate it as TM or SM. Search federal trademarks at www.uspto.gov. Have fun!