A trademark is a sign, logo or design of some kind that distinguishes a particular product or service (or its provider or source) from others.
A trademark identifies a particular product, service, or it's provider or source, from others, particularly in the same industry, but also in general. Often a mark will appear on product packaging, printed communication, and buildings.
Many countries require registration of a trademark in order for the owner, which may be an individual, company, or other legal entity, to pursue legal action for infringement.
Trademarks can be designated with the superscript TM (™), or the R in circle ® for registered trademarks.
Canonical answers:
- Difference in purpose and effect between trademark and copyright
- Do I need to designate trademarks (using ™ or ®) when referencing them?
- Registration
- Avoiding "trademark collision"
- What is the penalty for unauthorized use of the registered trademark symbol ®?
- How can I determine whether I can use a name commercially?
- Nominative Fair Use and a tricky example of it