The so-called welcome page is a website any user is shown on a regular interval. The main idea behind a welcome page is to enforce a user to read and accept the company's security policy and/or inform him that his Internet access is filtered or monitored.
There are several examples of how a welcome page can be implemented. This specific example uses the PDStorage feature of Secure Web Gateway (On-Prem) and redirects a user to an external website, which usually contains the company's terms of usage or other information a user needs to be aware of, such as company news, etc.
This example of the welcome page does not include a verification that a client has accessed, read, and understood the welcome page. As soon as the welcome page has been shown, the next request will be allowed.