Trade mark Ireland law protects the goodwill of a business. It allows you to distinguish your product or service from those of other companies, so that consumers know exactly what they're buying when they come across your trade mark.
To take advantage of this protection, however, it's important that you register your trade mark at an early stage in its development--and keep renewing it every 10 years thereafter. You also need to make sure that nobody else has registered or used any similar marks before yours came along; if they have done so, then there could be confusion among consumers as to who owns which products/services and where they can buy them.