EMZETT.Output (Output Device)
In short: Umbrella term for devices that output digital data in a form perceivable by humans — screen, printer, speakers.
In more detail: Output devices are the counterpart to input devices: they take in a digital signal and convert it into image, sound, or a physical result (a printout). Some devices are both at once (e.g. touchscreens: input and output in one).
In Depth
From digital signal to perceivable output
The path from digital signal to perceivable output runs via a graphics/sound card, which converts the raw digital data into a physical signal (e.g. pixel brightness values for the screen, electrical oscillations for the speaker). The operating system provides standardised interfaces for this (drivers, APIs like DirectX/OpenGL for graphics or WASAPI/CoreAudio for sound), so applications don’t need to know which specific output model is actually connected — a program simply calls “draw this pixel” or “play this sample”, and the driver translates that for the respective hardware.
Categories of output devices
- Visual output: screen, projector, e-ink displays (e-readers) — each with its own trade-offs between resolution, response time and power consumption.
- Acoustic output: speakers, headphones, vibration motors (haptic feedback is, in a broader sense, also a form of “output”).
- Physical output: printers (2D, paper), 3D printers (physical objects), plotters (large-format drawings/plans).
- Network output: in a broader sense, also network cards that “output” data to other systems — though usually not directly perceivable by humans.
Combined input/output devices
Some devices combine input and output in one device. A touchscreen shows an image (output) AND registers touch (input) — both functions run technically completely independently of each other (separate hardware layers stacked on top of each other), but appear to the user as a single, merged device. A headset microphone records sound (input) while the headphone part plays sound back (output). A modern printer with a scan function is also both: scanner (input) and printer (output) in one housing.
Latency and buffers
For real-time-critical output (especially audio, but also gaming displays), latency plays a big role — the time between “the application wants to output something” and “it actually arrives for the user”. Operating systems typically buffer output data (audio buffers, frame buffers for graphics), to avoid dropouts from brief delays — larger buffers mean more stable but slower (higher-latency) output, smaller buffers respond faster but risk crackling/stuttering under system load.