This page is a work in progress. I add words as needed based on the posts I publish.
Mode of Control The way in which a signal responds to real time traffic demand. On one extreme, a fixed-time intersection might have no real-time inputs (i.e. entirely pre-timed), and on the other extreme, a fully-actuated intersection will base all phases and durations based on real-time demand. The common middle ground is a semi-actuated intersection, where all but one of the phases are called and/or extended based on real-time demand. The City of Toronto covers the common examples here.
Leading left turn phase: The left turn precedes the corresponding through movement.
Lagging left turn phase: The left turn follows the corresponding through movement.
Permissive turn: Drivers wait for a gap in opposing traffic to proceed.