Which category of software can be used with partial functionality for no cost?

Public domain software is not restricted by copyright and is available for free use without any limitations. Unlike shareware, public domain software does not offer a trial version with partial functionality; instead, it allows unrestricted access to all features from the outset, making it fundamentally different from shareware.

Closed-source software is proprietary and typically requires a purchase for any functionality. Users cannot access or modify the source code, and there is no free version with partial features available. This category does not allow for any no-cost usage, as access is fully contingent on payment.

Freeware is software that is available for free and typically includes all its features without any restrictions. Unlike shareware, freeware does not provide a limited version for trial; it offers the complete software at no cost, hence differing in nature from the concept of partial functionality.