A unique identifier allows you to distinguish yourself from other researchers. It can be used in journal and grant submissions and it allows you to standardize your research persona ensuring that you get recognition for your work. It is now required by many funders and publishers.
ORCHID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. (From website)
Enter once, when you submit a paper, then watch as your ORCID record is automatically updated as your work is published, registered with Crossref, and enters the global citation network