As you have seen in many examples throughout this book, there are HTML elements denoted by <a> tags that contain href attributes that reference different URLs. These tags, called anchor tags, are how links are generated on a web page. In a web browser, these links would typically have a different font color, often blue, with an underline. As a user in a web browser, if you wanted to follow a link, you would usually just click on it and you would be redirected to the URL. As a web scraper, the clicking action is usually not necessary. Instead, you can send a GET request to the URL in the href attribute itself.
If you find that the href attribute lacks the http:// or https:// prefix and the hostname, you must use the prefix and hostname of the current web page.