ORCID is a free service for creating curated scholar profiles with a unique identifier. An ORCID ID is like a social security number for researchers. Once you have created an ORCID ID and associated your publications with that ID, search services like Google, SciFinder, and library search engines will know that you were the author of those publications.
If your name is Sarah Smith and you publish a paper, Google Scholar and other search engines will probably think you are the same as dozens of other Sarah Smiths who wrote totally unrelated things. However, if some Sarah Smith papers are linked to a specific ORCID ID, the search engines will know that the other Sarah Smith papers are probably written by someone else. That means search engines won't give someone else credit for your work. The data you put in ORCID can be harvested by other systems across the Internet to import your profile into other systems.
A nice feature in ORCID is that you can grant someone else permission to edit your profile. All you need to do is create a profile, grant someone permission, and send them your CV to ask for help.
You can enter publications manually or import them from certain publisher platforms. For instance, if you published in a journal indexed by Scopus or MLA, you can use the Search and Link tool to search and import works from those publishers.
ORCID mostly works behind the scenes, even if no one actually visits your profile. (Although, if someone does a Google search for your name, your ORCID profile will be high in the search results.)
The magic of ORCID is in linking your publications together. If someone finds one of your articles in Google Scholar, a library search engine, or a platform like ScienceDirect, they can click your name as an author. If you've set up a good ORCID profile, that link will allow the search engine to find other works you published without mixing up your name with other authors. Some platforms (like ScienceDirect) also link directly to your ORCID profile.