And, for images that need more explanation, add a caption.
ForMicrosoft Word Online, turn off the Simplified Ribbon.
However, if you want more control over the image placement, use the Word Insert menu.

Place the cursor where you want the image to appear.
Go to theInserttab, then selectPictures.
In Word 2010, selectPicture.

In Word Online, selectPictureorOnline Pictures.
In theInsert Picturedialog box, choose an image to insert into the document, then selectInsertorOpen.
To insert several images simultaneously, holdCtrland select each image.

To move the image, drag the image to a different location in the document.
To set a specific size for the image:
Right-tap the image, then selectSize and Position.
In theLayoutdialog box, go to theSizetab and selectLock aspect ratioto ensure that the height and width remain proportional.

Change the value in theHeightorWidthtext box to adjust the size of the image in inches.
To change the height and width by percentage, go to theScalesection and change theHeightorWidthvalue.
For example, make the image 75% or 120% of the size it was.

Images cannot be compressed in Word Online.
pick the picture you want to compress.
To compress all the images in a Word document, select any photo.

Go to thePicture Formattab and selectCompress Pictures.
In theCompress Picturesdialog box, selectApply only to this pictureto compress only the selected image.
Clear theApply only to this picturecheck box to compress all the photos in the Word document.
SelectDelete cropped areas of picturesto remove the parts of the images that were cropped.
Cropped areas are hidden so that you’re free to undo the crop.
When cropped areas are deleted, file size is reduced because cropped pieces are permanently removed.
If you’re not sure what to select, chooseUse default resolutionorUse document resolution.
For example, have the text wrap around the photo or insert the picture inline with the document text.
To change how the image appears in the document, opt for image, then go to theLayouttab.
In Word 2013 and 2010, go to theFormattab.
In Word Online, you could only customize the wrap text options, not the image layout.
To make this adjustment, selectFormat>Wrap Text.
How to Add a Caption to a Photo in Word
A caption clarifies your picture to readers.
Captions are not supported in Microsoft Word Online.
To add a caption, right-snag the image and selectInsert Caption.
SelectNumberingto configure automatic captioning based on a specific number style or chapter number.
To edit the caption, highlight the text and key in a new caption.