Sometimes the text is blue and then changes color after you have clicked on it. The color change indicates that you or someone who recently used this computer visited that site. Blue words will take you places. Purple words will also take you somewhere. Their color indicates you have recently clicked on them.
Black text goes nowhere.
Normally when you click on some hypertext, the new page that appears will be an expansion of the topic related to the hypertext. For example you can click on this hyper text link to find out more about what a white mouse looks like. In my example I have used blue and purple as examples of hypertext, however linked text may be green, orange, purple, etc. An easy way to tell if text is hypertext is to put the cursor over it. If it turns into a hand with a pointing finger the text is a link.