Originally developed by Forethought, who Microsoft bought out, PPT is the worlds most popular presentation file format. It is a very powerful tool that you can use to create presentations that include pictures, graphs, text and many other objects. Many businesses and students that have to present something will almost always do their presentation using Microsoft PowerPoint.
A large part of any presentation is how the text enters, appears and exits the screen. Entrance, emphasis, and exit of elements on a slide itself are controlled by what PowerPoint calls Custom Animations Transitions. These can be animated in a variety of ways. For example you can customise the animation to create small story boards by animating pictures to enter, exit or move. With different type of callouts, speech bubbles with edited text can be sent on and off to create speech. The overall design of a presentation can dictate how all the other slides appear and operate, this is called a master slide. Everything from design to the text on the slide can be edited using a primitive outliner.
Developed in 1982 by Adobe Systems, the .ps extension is a file type used by the publishing industry. Prior to the development of PostScript, it was not possible to print images and text on the same page. Postscript addressed this by defining a language that allowed applications to instruct the printer how to display objects on the page. This file type revolutionised publishing allowing certain curved items to be printed that previously could only be printed on specialist CAD printers. Although no longer as popular or common as it was historically, it is still an important file type.
PostScript is actually a programming language as well as a file type. Typically files are created by applications such as Adobe Acrobat or Quark Xpress. Now a legacy file format, most printers and programs continue to support this format, with the only pre-requisite being a printer utility that supports PostScript. The file basically contains a set of instructions that tell the printer what to print and provide the co-ordinates on the page of where an object or text should be printed.
