You can show an image that lives alongside the HTML page code, in another folder, or somewhere else on the Internet. You can also change the size of the image that is displayed.

Here is an image of a some shapes:

pink star and some random shapes on a blue background

The command to show this image, which lives right with this page's HTML code is:
<img src="shapes.gif">

The original image is 320 pixels wide. Here is the same image, from the same file, smaller, only 200 pixels wide:

star image half size

The command to show this image, which lives right with this page's HTML code is:
<img width=200 src="shapes.gif">

Here is the Northeastern University logo. I have a copy in a different folder on my web host:

image in a different folder - Northeastern logo

The command to show this image is:
<img src="../../../personal/northeastern_logo.gif">

Finally, you can use an image that resides at another web site, though it will take a LOT longer to download and display.
silver Alfa Romeo 166 sedan

The command to show this image is:
<img src="http://www.alfaromeo.it/ALFAROMEO_ITALIA/uploads/1030/1073817916/20030929/01.Frontale_Strada_3.jpg">

This is a picture of the Alfa Romeo model 166 from their site in Italy.