If you need to grab an image from a PDF, Web or Document
There are a couple of tools you can use built into your computer or mobile device.
Like: Printscreen (PC) or ScreenClip (Mac)
Computer or Laptop
PrintScreen button (PC Windows 7)
(usually) on the upper left hand corner of the PC keyboard
1. Press PrtScn.
2. Open Paint by clicking the Start button , clicking All Programs, clicking Accessories, and then clicking Paint.
3. In Paint, on the Home tab, in the Clipboard group, click Paste.
4. If you want to resize the image, on the Home tab, in the Image group, click Resize, and enter a new percentage or pixel size.
5. Click the Paint button , and then click Save.
It’s also possible to capture a specific active window when you press PrtScn.
Screen Clip (Mac)
Take a screenshot of part of your screen
1. Press Command (⌘)-Shift-4. You’ll see that your cursor changes to a crosshair pointer.
2. Move the crosshair pointer to where you want to start the screenshot.
3. Drag to select an area. To adjust the area, hold Shift, Option, or the Space bar while you drag.
4. When you’ve selected the area you want, release your mouse or trackpad button. Or to cancel, press Escape (esc).
5. Find the screenshot as a .png file on your desktop.
On your Phone or Tablet
Press and hold the Sleep/Wake button on the top or side of your iPhone, iPad, or iPod touch, then immediately press and release the Home button.
You can find the screenshot in your Photos app.
This may vary on android devices.