ORCID stands for Open Researcher and Contributor ID. An ORCID id is a persistent digital identifier that you own and control, and that distinguishes you from every other researcher.https://orcid.org/ It is not necessary to have an ORCID to be a prolific and proficient published author, but it is often easier to track your published articles and see your combined output in one place.
When submitting a paper for publication, many editors will ask for the authors' ORCID numbers, if they have one. If you have an ORCID and provide that number to the publisher, ORCID will automatically know when your paper is published and will add it to the running list of published papers you have authored.
The website above has links to create an ORCID number. You can also use the Search box to locate researchers (including yourself) to find your ORCID number or see a compilation of publications.