They can be text links or images. Text links are underlined. Some website authors choose different colours. We do not think this is a good idea. The words used, or the picture or words in the image should tell you that this is a link and what you will see when you get there.
Some images change colour or shape when the cursor is near.
This is called Hover. In any case the cursor will change from being a pointer to a pointy-hand when over a link. And the status bar at the bottom of the display should show the URL of the destination. There will often be a menu of pages that you can visit on the website. Or on larger websites there may be a Sitemap with all the available pages listed.