What is a trademark?

The Canadian Intellectual Property Office, called the CIPO, so defines the trademark:

Trademark can consist of one word, symbol or drawing (or a combination of these), used to distinguish the products or services of one person or organization from those of others offered in the market. Trademarks come to represent not only the real goods or services but also the reputation of the producer. As such, they are considered as valuable intellectual property. A registered trademark can be protected from misuse and imitation by contentious proceedings.