When you insert several images into your Word document the images will increase the file size which might cause problems for navigation and scrolling within the document. That is why the user has a need to compress the image in a Word document. Or you can save space in your hard disk and reduce download size and time. You could compress some images without losing quality and reduce image resolution.
To compress images use the following prcedure.
Insert a picture into your Word document:
Select the picture which appears in the "Format Tab".
Now click on the "Format Tab" and choose the "compress picture" option within the "Adjust" group.
The Compress Picture Window opens where you can change the compress option then click Ok to reduce the picture size.
Note: Now you will see the size of you picture reduced.