A trademark is a word logo symbol or any combination of these, is a mark that is associated with the identity of your business which distinguish between your product and services from other businesses.

It is a unique identity that gives recognition to your business in market as your own. Example of trademarks:
Like BATA we all know that it is associated to a company that produces footwears. Colgate is a trademark associated with toothpaste.
A trademark gives you a easy identification to your product and services in market full of competitors.