PageReference can be used to navigate from the current page to a different page using Salesforce Apex.

The below code is used to open new page ‘AddAllBlog’ from current page.

Apex Code:

public PageReference skip() {  
  PageReference pg = new PageReference('/apex/AddAllBlog');
  pg.setRedirect(true);
  return pg;  
}

If you give URL as ‘http://google.com’ instead of ‘/apex/AddAllBlog’, it will open google website.