Software that can be installed and used, and then purchased if you decide to continue using it, is called:

The correct answer is shareware. Shareware is a type of software that allows users to download and use it for a limited period of time or with restricted features, encouraging them to try it out before making a purchase decision. This model enables users to evaluate the software’s functionality and determine whether it meets their needs before committing to a financial investment.

In contrast, freeware is software that is available for use at no cost but does not typically offer a purchase option for additional features. Trialware, while closely related to shareware, often refers specifically to software with a defined trial period after which it may become unusable unless purchased. Open-source software is different altogether, as it allows users to view and modify the source code without any cost, but it does not fit the criteria of needing to purchase it after a trial period. Shareware effectively balances evaluation and potential purchase, making it a popular choice among software developers for distributing their products.