How To Capture a Screen Shot with Mac OS X

by: ebenjie
..this is one of the ways to capture a screen shot with mac os x

1. To capture the entire desktop, press Command-Shift-3. The screen shot will be automatically saved as a PNG file on your desktop.

2. To copy the entire desktop, press Command-Control-Shift-3. The screen shot will be placed on your clipboard for you to paste into another program.

3. To capture a portion of the desktop, press Command-Shift-4. A cross-hair cursor will appear and you can click and drag to select the area you wish to capture. When you release the mouse button, the screen shot will be automatically saved as a PNG file on your desktop. (The file is saved as PDF in Mac OS 10.3 and earlier.)

4. To capture a specific application window, press Command-Shift-4, then press the Spacebar. The cursor will change to a camera, and you can move it around the screen. As you move the cursor over an application window, the window will be highlighted. The entire window does not need to be visible for you to capture it. When you have the cursor over a window you want to capture, just click the mouse button and the screen shot will be saved as a PNG file on your desktop. (The file is saved as PDF in Mac OS 10.3 and earlier.)

..Different versions of Mac OS X have different formats for screenshots.

Mac OS X 10.2 (Jaguar): jpg
Mac OS X 10.3 (Panther): pdf
Mac OS X 10.4 (Tiger) and later: png

terms:
- clipboard is a software facility that can be used for short-term data storage and/or data transfer between documents or applications, via copy and paste operations. It is most commonly a part of a GUI environment and is usually implemented as an anonymous, temporary block of memory that can be accessed from most or all programs within the environment via defined programming interfaces. A typical application accesses clipboard functionality by mapping user input (keybindings, menu selections, etc.) to these interfaces.

- PNG (Portable Network Graphics) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace GIF (Graphics Interchange Format) as an image-file format not requiring a patent license. The PNG acronym is optionally recursive, unofficially standing for PNG's Not GIF.

- PDF(Portable Document Format) is an open standard for document exchange. The file format created by Adobe Systems in 1993 is used for representing two-dimensional documents in a manner independent of the application software, hardware, and operating system.[2] Each PDF file encapsulates a complete description of a fixed-layout 2D document that includes the text, fonts, images, and 2D vector graphics which compose the documents. Lately, 3D drawings can be embedded in PDF documents with Acrobat 3D using U3D or PRC and various other data formats.

- JPG (Joint Photographic Experts Group) is a commonly used method of lossy compression for digital photography (image). The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality.

source: http://guides.macrumors.com/Taking_Screenshots_in_Mac_OS_X