behavior formula (Power Apps)
Power Appsの式のうちアプリの状態を変えるような副作用を持つ式のこと。
https://docs.microsoft.com/en-us/power-apps/maker/canvas-apps/working-with-formulas-in-depth
Because these functions change the state of the app, they can't be automatically recalculated. You can use them in the formulas for the OnSelect, OnVisible, OnHidden, and other On... properties, which are called behavior formulas.
関連ページ
https://docs.microsoft.com/en-us/power-apps/maker/canvas-apps/working-with-formulas