What is Digital Video?
Digital video is a sequence of still images (frames) played back rapidly to create the illusion of motion
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Digital Video: Simple Definition
Digital video is a sequence of photographs (frames) displayed in rapid succession to create the illusion of movement. Just like a flipbook, when individual still images are shown fast enough, the human eye perceives smooth motion.
Standard video plays 24, 30, or 60 frames per second (fps). At 30fps, a 1-minute video contains 1,800 individual image frames. Without compression, this would be enormous - that's why video codecs like H.264 and H.265 are essential.
Why Video Compresses So Well
Successive frames usually differ only slightly, so video codecs encode most frames as changes from neighboring ones rather than as full pictures.[3] Self-contained keyframes are interspersed with predicted frames that store only motion and differences, which is how an hour of footage shrinks to a fraction of its raw size.[3]
Frame Rate and Scanning
Beyond resolution, video is defined by its frame rate and whether it is progressive (each frame drawn whole) or interlaced (alternating half-frames of odd and even lines), a legacy of broadcast television.[3] Higher frame rates smooth fast motion but multiply the data the codec must handle.[3]
Streams Inside a Container
A finished video file is rarely a single thing: a container interleaves the compressed video with one or more audio tracks, subtitles and metadata, keeping them in sync during playback.[1] Utilities like FFmpeg can extract, transcode or repackage these individual streams.[2]
How Digital Video Works
Modern video codecs do not store every frame as a complete image. They store a full frame (keyframe) and then only the differences between that frame and subsequent frames. A static background only needs to be stored once, not in every frame.
This temporal compression is why a 10-minute video in H.264 might only be 500MB when the raw uncompressed frames would be 100GB+. The codec's efficiency directly determines the trade-off between file size and quality.
Examples of Digital Video
24fps
Cinema standard. Creates the classic “film look” with slight motion blur.
30fps
Standard for TV and web video. Smooth for most content types.
60fps
Smooth motion for sports, gaming, and action. Twice the data of 30fps.
120fps and above
Used for slow motion. A 120fps video can be slowed to 4x without frame drops.
Work With Your Files
Now that you understand the concept, use our free tools to convert, compress, and optimize your files.
Try Video Converter FreeFrequently Asked Questions
What is fps in video?
Frames per second (fps) is how many still images make up each second of video. 24fps is cinema standard; 30fps is TV standard.
What resolution should I record video at?
1080p for most uses. 4K if you plan to crop, stabilize, or want future-proof footage.
What is a keyframe?
A keyframe is a complete video frame. Most frames only store changes from the previous keyframe, saving storage space.
Why are video files so large?
Video contains many images per second. A 1080p30 video has 2 million pixels x 30 frames = 60 million pixels per second to encode.
What is the best format to save video?
MP4 with H.264 for maximum compatibility. MKV for archiving with multiple audio tracks. WebM for web embedding.