If you have a Mac or iMac and you are not using the Preview app then you definitely are missing out on a lot things. Preview app combines the functionalities of two applications into a single editor: it allows you to view and edit both photos and PDFs. As a teacher, you can use this app to prepare your visuals and annotate PDFs to include in your instruction. Preview app offers you a bunch of powerful editing features all for free. In today’s post, we are going to show you some the things you can do with this app:
I- For images, Preview app allows you to:
- Open and view a variety of image types including: TIFF, PNG, JEPG, GIF, BMP, and PDF.
- Select any area in the image and cut or copy it to clipboard
- Select and remove backgrounds or other objects from photos (this daily works with PNG)
- Add different shapes to your images(e.g rectangle. ellipse, or line tools)
- Add text to your images
- Adjust the colour and size of your images
To open an image using Preview, double click on it or drag and drop it into Preview icon in Finder or Dock. Once opened, you can use the tools in the toolbar to edit your images. Here is some of what you can do with these tools:
A- Change the magnification of your image using the scale up
and scale down 
buttonsB- Click on ‘Show Markup Toolbar’ to open the editing toolbar then choose from the tools below:
C- Use this tool
to crop your image or copy/ cut a portion of your image into your clipboard. It offers different selection formats:
D- Use Instant Alpha tool
to remove a background or other objects from your imageE- Use the Rectangle
, Ellipse 
or Line tools to add shapes to your image.F- Use the Text tool
to add a text to your image. ‘Click and hold the Text tool button to see additional options such as speech bubbles and thought bubbles.’G- Use this tool
to adjust the colour of your image.II- For PDFs, Preview app allows you to:
- Open and view PDF files
- Highlight selected areas in a PDF
- Add a text box and type in your text in a PDF
- Add shapes to a PDF
- Add notes and comments
- Fill in form blanks in a PDF
- Insert your a digital image of your signature into a PDF
Here is how to annotate your PDF documents using Preview. Once you open your PDF in Preview, click on ‘Show Markup Toolbar’ to open the editing toolbar then choose from the tools below:
A-
Use this tool to select text in your PDF which you can then copy and paste into any text editor of your choice.B-
: Use this tool to add a text box anywhere in your PDFC-
: Use this tool to add a variety of shapes to your PDFD-
Use this tool to add notes to your PDFE-
: Use this tool to insert your signature into a PDF documentCheck out this page to learn more about how to use Preview App
Source: Apple Support
