ORCID provides a unique scholar identifier to help you get credit for all your research/professional contributions. When integrated with online publisher services and databases, it helps online searchers find your work and helps publishers, funding agencies, universities, and professional associations distinguish you from others with the same or similar name.
See an example of an ORCID profile here: http://orcid.org/0000-0002-1825-0097
Most author identifiers are intended for use in a specific national, proprietary, or disciplinary system. Unlike other IDs, ORCID is “platform-agnostic, discipline neutral, and publisher-independent”