File formats and terms reference

An extra image channel that defines the transparency of every pixel.

BMP file format: extension, MIME type and available conversion directions.

The print colour model: cyan, magenta, yellow and key black inks.

CSV file format: extension, MIME type and available conversion directions.

DOC file format: extension, MIME type and available conversion directions.

DOCX file format: extension, MIME type and available conversion directions.

Dots per inch: the pixel density of a scan or a print.

EPUB file format: extension, MIME type and available conversion directions.

The suffix of a file name that tells the system which program to use.

Storing typefaces inside the file so the document looks the same anywhere.

GIF file format: extension, MIME type and available conversion directions.

HTML file format: extension, MIME type and available conversion directions.

JPG file format: extension, MIME type and available conversion directions.

JSON file format: extension, MIME type and available conversion directions.

Reducing file size while keeping the data byte-for-byte recoverable.

Shrinking a file by discarding data the eye barely notices.

A string such as image/png that tells servers and browsers what the content is.

Optical character recognition: turning a picture of text into editable text.

ODP file format: extension, MIME type and available conversion directions.

ODS file format: extension, MIME type and available conversion directions.

ODT file format: extension, MIME type and available conversion directions.

PDF file format: extension, MIME type and available conversion directions.

Characters stored alongside the page image — search and copying rely on it.

A subset of PDF meant for long-term archival storage.

PNG file format: extension, MIME type and available conversion directions.

PPT file format: extension, MIME type and available conversion directions.

PPTX file format: extension, MIME type and available conversion directions.

A colour model built from red, green and blue channels — used by screens.

RTF file format: extension, MIME type and available conversion directions.

An image stored as a grid of pixels, each with its own colour.

SVG file format: extension, MIME type and available conversion directions.

A PDF that contains only page images: the text cannot be selected or searched.

TIFF file format: extension, MIME type and available conversion directions.

TXT file format: extension, MIME type and available conversion directions.

Detecting rows and columns on an image and rebuilding them into a table.

The rule that maps characters to bytes when a file is saved.

An encoding that covers the characters of every writing system at once.

An image described by curves and shapes instead of a pixel grid.

Building vector outlines from a raster image.

WEBP file format: extension, MIME type and available conversion directions.

XLS file format: extension, MIME type and available conversion directions.

XLSX file format: extension, MIME type and available conversion directions.