25 essential terms and definitions for understanding digital file formats, compression, and conversion.
A compression method that reduces file size by permanently removing some data. Common in JPEG images and MP3 audio. Smaller files but some quality loss.
A compression method that reduces file size without any data loss. The original file can be perfectly reconstructed. Used in PNG, FLAC, and ZIP.
Software that encodes and decodes digital data, especially for audio and video. Examples: H.264, H.265, VP9, AAC, Opus.
A file format that can hold multiple types of data (video, audio, subtitles, metadata) in a single file. Examples: MP4, MKV, AVI, WebM.
The amount of data processed per unit of time, usually measured in kbps or Mbps. Higher bitrate generally means better quality but larger file size.
The number of audio samples captured per second, measured in Hz. CD quality is 44,100 Hz (44.1 kHz). Higher rates capture more detail.
The number of pixels in an image or video frame, typically expressed as width × height (e.g., 1920×1080 for Full HD).
The number of bits used to represent the color of a single pixel. 8-bit = 256 colors, 24-bit = 16.7 million colors, 32-bit adds transparency.
An additional channel in image formats that stores transparency information. Supported by PNG, WebP, TIFF, and GIF (binary only).
Images defined by mathematical equations rather than pixels. Can be scaled infinitely without quality loss. Common formats: SVG, EPS, AI.
Images made up of a grid of pixels. Quality degrades when scaled up. Common formats: JPEG, PNG, GIF, BMP, WebP.
A measure of print resolution. 72 DPI is standard for screens, 300 DPI is standard for print. Higher DPI means sharper prints.
Data that describes other data. In files, this includes creation date, author, camera settings (EXIF), GPS coordinates, and more.
Exchangeable Image File Format data embedded in photos. Contains camera model, exposure settings, date, GPS location, and other shooting information.
Optical Character Recognition — technology that converts images of text into machine-readable text. Used to make scanned PDFs searchable.
Converting media from one codec/format to another. For example, converting H.264 video to H.265 for smaller file sizes.
Converting multiple files simultaneously rather than one at a time. Saves time when processing large numbers of files.
The suffix at the end of a filename (e.g., .pdf, .jpg, .mp3) that indicates the file format and helps the operating system choose the right application.
A standard identifier for file formats on the internet (e.g., image/jpeg, application/pdf). Used by web servers and browsers to handle files correctly.
The proportional relationship between width and height. Common ratios: 16:9 (widescreen), 4:3 (standard), 1:1 (square).
The number of frames displayed per second in video, measured in fps. 24fps is cinematic, 30fps is standard, 60fps is smooth.
Two methods of displaying video. Interlaced (i) draws odd/even lines alternately. Progressive (p) draws full frames. 1080p is better quality than 1080i.
A technique that compresses color information more than brightness. 4:4:4 is uncompressed, 4:2:0 is most compressed. Used in JPEG and video codecs.
Unprocessed image data directly from a camera sensor. Contains maximum detail for post-processing. Large file sizes. Common: CR2, NEF, ARW.
An ISO-standardized version of PDF designed for long-term archiving. Ensures documents remain readable regardless of software changes.