What is software that is free to download but has limited functionality until purchased called?

The term for software that is free to download and use, but comes with limited functionality until a purchase is made, is known as shareware. This model allows users to test the software and explore its capabilities before committing to a purchase, creating an opportunity for developers to attract users who may later convert to paying customers.

Shareware often includes features that are fully operational for a limited period (trial version) or with limited options available until the user pays for the full version. This allows individuals to assess the utility and performance of the software in real-world conditions before deciding to invest in the complete product.

The other terms do not fit this definition as precisely. Freeware refers to software that is completely free without limitations, proprietary software is commercial software that is not open for modification or redistribution, and open-source software is freely available with the source code for anyone to modify and distribute.