Screen Capture
The process of recording everything displayed on your screen as a video file or image.
Screen capture is the act of recording your screen’s contents — everything displayed at a given moment — as a video or still image. The result is a screen recording (video file) or screenshot (image file).
How screen capture works
Modern operating systems expose screen capture through OS-level APIs:
- Windows: DXGI (DirectX Graphics Infrastructure) — used by OBS, Camtasia, and most Windows screen recorders. Allows capturing individual windows, regions, or the full display.
- Mac: AVFoundation / CoreMediaIO — used by ScreenFlow, QuickTime, and Loom’s Mac client. Apple Silicon Macs added DisplayLink capture in macOS 12.3.
- Browser: MediaStream API (W3C) — used by Loom’s browser extension, ScreenPal Web, and Screencastify. The browser asks permission to share a tab, window, or full screen.
The API choice matters because browser-based recorders (Loom Chrome extension, ScreenPal Web) are limited to what MediaStream exposes — typically 30fps max, and they cannot capture DRM-protected content. Native apps (OBS, Camtasia, ScreenFlow) use OS APIs directly and can capture at 60fps+, including more protected content.
Capture types
| Type | What it captures | Common use |
|---|---|---|
| Full screen | Everything on one monitor | Tutorial recordings, demos |
| Window | One specific app window | Bug reproductions, software reviews |
| Region | A defined area of the screen | Close-up demos, UI detail |
| Browser tab | One tab in a web browser | Web app demos, LMS recordings |
| Game capture | GPU frame buffer | Game recordings, high-fps content |
Why it matters in buying decisions
The capture type you need affects which tool you can use. Xbox Game Bar only does game capture — it cannot record File Explorer or a desktop app. Loom’s free browser extension only does browser tab/window capture. OBS Studio can capture any source, including windows, regions, webcams, and game frames simultaneously.
Before choosing a tool, identify: do I need to capture the full screen? A specific app? A browser tab? That answer alone eliminates several tools from contention.
Related concepts
- Async video — what screen captures are used for in team communication
- Lossless recording — capturing at maximum quality before compression
- Video compression — what happens to the capture before you share it