Sometimes, an applicant enthusiastically applies for many job postings. Based on their experience and requirements, they might just end up in consideration for more than one job posting. When a candidate exists simultaneously in many live hiring processes, we refer to these candidate as 'Duplicate Candidates'.
A duplicate can be easily identified by the little 'person' icon that marks their profile.
If you want to figure out the other jobs this particular candidate has applied for, you can hover over the candidate's name, in the list and kanban view, to see a list of jobs. The green swoosh (tick) indicates whether the candidate is active in the specific job posting.
You can also view this information by checking their Candidate 360. Go to Profile> Applicant Tracking System Info, in their Candidate 360, to find a list of the jobs they've applied for.