A Termux package mainly just containing scripts to call and initialize certain functionality for the Termux:API
Application Programming Interface optional add-on available from F-Droid and https://github.com/termux/termux-api
They are optional and not a requirement for Termux to function, but it does extend the capabilities of Termux. It also enables some additional extra features since it basically enhances communication between Termux and the Android Operating System