If you need to show an expert an error message on your system, create instructions for performing a task, or even contribute to a wikiHow article, a screenshot is the perfect way to show someone exactly what is happening on your computer screen.
Steps
Method 1 of 7: Make a full screen copy

Step 1. Make sure your screen is showing exactly what you want to capture
Make sure all affected windows are visible.

Step 2. Press Command + Shift +3
If sound is on, your computer should emit a short shutter sound.

Step 3. Find your screenshot on your desktop
It will be saved under the name "screen" plus the date and time.
With older versions of OS X, it will either be saved as Image # (with # representing a number, for example, if this is the 5th screenshot of your desktop, the file will be named Image 5) be in the form of a screenshot labeled with the date and time
Method 2 of 7: Take a screenshot of a specific area of the screen

Step 1. Press Command + Shift + 4
Your cursor will turn into a small crosshair in the shape of a cross.

Step 2. Click and drag your cursor to select the area you want to capture
A shaded rectangle should appear when you drag your cursor. If you need to readjust your windows to the area you want, press Esc to return to the normal cursor without capturing anything.

Step 3. Release the mouse
You should hear a short shutter sound if your computer sound is on. This means that your screen capture has been taken.

Step 4. Find your screenshot on your desktop
It will be saved in a-p.webp" />
Earlier versions of Mac OS X will save the screenshot as “Picture #.” If this is the 5th screenshot on your desktop, it will be named “Picture 5”

Step 5. Use the screenshot
Once you've taken your screenshots, they're ready to use as you need them. You can attach them to an email, upload them to the web, or even drag them right into an app like a word processor.
Method 3 of 7: Take a screenshot of the open window

Step 1. Press Command + Shift + 4 and press the space bar
The cross turns into a small camera. You can press the space bar again to return to the crosshair.

Step 2. Move your cursor over the window you want to capture
The camera highlights the different windows in blue when it moves over them. You can use keyboard commands like Command + TAB to switch between windows while staying in this mode.

Step 3. Click on the window
The window image you selected will be saved to the desktop by default, just like with other screen capture methods.
Method 4 of 7: Save screenshot to clipboard

Step 1. Press Command + Ctrl + Shift + 3
This method works just like the one above, except the screenshot does not immediately create a file. Instead, the image is saved to the clipboard, that temporary storage area where your computer stores the text you copied.
You can also capture a portion of the screen with this method by using Command + Ctrl + Shift + 4 and dragging your crosshairs to the appropriate part of your screen, just like in the partial screenshot method above

Step 2. Use Command + V or Edit> Paste to paste your image
Your screen image can be pasted directly into any compatible application, such as a Word document, image editing program, and many email services.
Method 5 of 7: Use the Grab app

Step 1. Go to Applications> Utilities> Grab
This opens the Grab app. You will see the menus displayed in the upper left corner of your screen, but no window will open.

Step 2. Click on the Capture menu and choose the appropriate one from the four different options
- To take a photo of your entire screen, click Screen (or just use the Apple + Z keyboard command). A popup window will tell you where to click and let you know that this pop-up window will not appear in the screenshot.
- To capture part of your screen, click on the selection. A window will appear asking you to drag your mouse over the part of the screen you want to capture.
- To capture a specific window, select Window. Then click on the window you want to capture.

Step 3. When the new window opens, choose Save
You can also choose Save As to give it another name and / or save the screenshot to a more suitable folder, but note that it can only be saved in.tiff format. Note that the file is not saved automatically.
Method 6 of 7: Change the default location for saved files

Step 1. Create a new folder
Do this in the Finder by clicking File> New Folder.

Step 2. Name the folder
Do this by clicking once on "Untitled Folder". Enter the name you have chosen in the box, for example "Screenshots".

Step 3. Open a terminal window
This can be found in the Finder, in Utilities.

Step 4. In the command line, copy defaults write com.apple.screencapture location, making sure to include a space after location
Do not click Return.

Step 5. Drag the folder you chose into the terminal window
This will add the new destination to the command line.

Step 6. Click Back
A new command line appears.

Step 7. Copy killall SystemUIServer to the command line and press Enter
This will reset the terminal, which will cause the changes to take effect immediately.

Step 8. Be careful not to delete the folder
Otherwise, you will have to recreate or repeat this process to assign a new default location to your screenshots.
Method 7 of 7: Employ other options

Step 1. Use Skitch
Skitch will allow you to make basic edits to your screenshots and upload them to the web.

Step 2. Monosnap is a powerful screen capture tool
Take a screenshot, annotate it and upload it to the cloud, open or save it in any other external editor.

Step 3. Use Jing
Similar to Skitch, Jing allows you to take screenshots and upload them directly to the web. You can also use it to take videos of your screen.
Advice
- Advanced users with knowledge of the Mac OS X Lion Terminal application can also use the "screen-capture" command to take a screenshot from the command line.
- An alternative, but time-consuming, method of taking screenshots is available through the Mac OS X Lion preview. The screen options appear in the "File" menu and correspond to those available through keyboard shortcuts.
- Files created with the screenshot tool are saved to the desktop by default as-p.webp" />
Warnings
- When taking screenshots for transmission to others or for posting on the Internet, make sure that no personal or confidential information is captured in the image.
- Posting screenshots that include protected information could have legal implications, so be careful and make sure that you have the right to enter all the information visible on your screen.