- pads
- Rubber squares for finger drumming or launching clips, usually velocity-sensitive and often pressure-sensitive with RGB backlighting. 8 or 16 pads on keyboards; 64 on grid controllers.
- clip launching
- Triggering loops and scenes from a grid, Ableton Live Session View style. Grid controllers like the Launchpad and APC exist mainly for this.
- faders
- Sliders, typically nine (eight tracks plus a master) mapped to mixer levels or drawbars. 60 mm is the usual travel on controllers.
- knobs
- Rotary controls with a fixed start and end (about 270° of travel). Cheap and direct, but the position may not match the software value when you switch presets.
- encoders
- Knobs that turn forever. Because they send relative "up a bit / down a bit" messages, they never jump the software value. Ideal for DAW and plug-in control.
- pitch bend
- A spring-loaded wheel (or strip, joystick or lever) that bends the pitch of held notes up or down. Usually paired with a modulation wheel.
- mod wheel
- A free-moving wheel that sends a continuous control, conventionally vibrato depth, but assignable to anything.
- touch strips
- Flat capacitive ribbons standing in for pitch and mod wheels on slim controllers. Lighter and cheaper, with less tactile feedback.
- joystick
- A single stick doing pitch bend on one axis and modulation on the other. Saves space on mini controllers.
- arpeggiator
- Holds a chord and plays its notes one at a time in a pattern, synced to tempo. Handy for instant rhythmic parts.
- sequencer
- Records and plays back a pattern of notes from the controller itself, useful for driving hardware synths without a computer.
- scale mode
- Restricts the keys or pads to a chosen scale so every note you hit is "in key". A safety net, or a way to play melodically on a pad grid.
- chord mode
- Plays a full chord from a single key or pad, either a fixed voicing you set, or chords chosen to fit the selected scale.
- note repeat
- Holding a pad retriggers it in time with the tempo (8ths, 16ths, triplets…). The MPC trick for hi-hat rolls and trap hats.
- display
- Screen for parameter names and values. OLED is the small monochrome panel on most mid-range controllers; a colour LCD shows more but costs more.
- Hall-effect
- A contactless way of sensing movement: a magnet sits on the moving part and a sensor reads the strength of its field, so nothing rubs and nothing wears out. Because the sensor reports how far something has travelled rather than just whether it has been pressed, a Hall-effect button or key can send continuous pressure or position as well as a note, and it will not develop the crackle or dead spots that eventually affect mechanical contacts and carbon-track faders.
