PawPrint.net Glossary of Terms

A simple, very flexible text format derived from SGML (ISO 8879). Originally designed to meet the challenges of large-scale electronic publishing, XML is also playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere.

RAM is a type of computer storage whose contents can be accessed in any order. This is in contrast to sequential memory devices such as magnetic tapes, discs and drums, in which the mechanical movement of the storage medium forces the computer to access data in a fixed order. It is usually implied that RAM can be both written to and read from, in contrast to read-only memory or ROM.

Computers use RAM to hold the program code and data during execution. In the first electronic computers, RAM wa...

Abbreviated as PDL, a language for describing the layout and contents of a printed page. The best-known PDLs are Adobe PostScript and Hewlett-Packard PCL (Printer Control Language), both of which are used to control laser printers.

Both PostScript and modern versions of PCL are object-oriented, meaning that they describe a page in terms of geometrical objects such as lines, arcs, and circles.

ls [options] [names]

List the contents of a directory or directories. This is similar to the dos command ´dir´ frequently abbreviated in many shells to ll for ls -l which lists files with long format. If no [names] then the contents of the current directory are listed.

Options
-1, --format=single-column
Print one entry per line of output.

-a
List all files, including the normally hidden files whose names begin with a period.

-b, --escape
Display nonprinting characters in octal an...

The opening of a lens that admits light. Except in very simple cameras, the Aperture can be varied in size by an adjustable  diaphragm, which regulates the amount of light passing through the lens. The relative Aperture is measured as the focal length of the lens divided by the diameter of the Aperture; this is expressed as an f-number: f/3, f/5, and so on.

Aperature has a dramatic effect on the Depth-of-field of the photograph.

An extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. Indexed-color, grayscale, and truecolor images are supported, plus an optional alpha channel for transparency. Sample depths range from 1 to 16 bits per component (up to 48bit images for RGB, or 64bit for RGBA).