The Jedi Knight uses a Focus system where the player builds up action points using one kind of ability, and then depletes the resource using other abilities.
The most basic attack named Strike generates one Focus per each successful hit, while Slash consumes three Focus per activation.
The combat itself feels very combo-based; the biggest determinant of successful combat was to string together efficient attacks that build and consume Focus at a constant rate to deal the most damage.
The first few levels of a Jedi Knight revolve around using Strike three times, and then the Slash ability when your Focus allows. This mechanic doesn't change much later on, and it grows in scale as you gain more abilities.