Organizations represent the employer on which the user is acting on behalf of.
An organization may be comprised of multiple legal entities distributed geographically, e.g. headquarters located in Geneva plus a branch office located in Berlin.
Every organization (organizational unit) can be verified legally if requested.
Additionally, every organization can provide their self-assessment using the data.org data maturity assessment tool.
These type of verifications/assessments help data-providers to feel more confident that the data they share is in responsible hands.