A trade mark is something that is used to distinguish your goods or services from those of other businesses. A trade mark may be a business name, product name, tag line, aspect of your packaging, logo or something else that you use to help your clients identify your brand amongst the sea of competitors.
A trade mark can be registered or unregistered. While owners of unregistered trade marks do have legal rights, it is easier for owners of a registered trade mark to enforce their rights.
For more information take a look at my blog post: What is a trade mark?