What Is Entity Resolution?
Entity resolution is the process of working out which records describe the same real-world person or company when they are written differently and share no common ID.
How matching works
Resolution matches records on keys: a profile URL, an email address, a company ID. Strong keys give confident matches. Weak keys such as names and domains give candidates that need a check, because two different people can share a name and two companies can share a domain.
Where it goes wrong
Two errors matter. A false merge joins two different entities into one record. A false split leaves one entity as two records. Merges are the more damaging error, because they mix histories that cannot be separated afterwards, so a cautious system prefers to leave a doubtful pair apart.
How it works in the Kooperativa API
The reverse email lookup resolves an email address to a person's profile record, which is useful when an email is the only identifier you have. Once you have the profile, take the company ID from it and store that, so later matches use a strong key.