These are actually interchangeable terms that, more or less, mean the same thing. More often than not, you hear “web browser” or “internet”, without the browser. A page browser is implied when you are using the other terms. They’re all web pages, internet pages. Sometimes, you do refer to it as a simple page, but more often than not, you’re not using just one term.
All these softwares usually come pre-downloaded on the computer that you’re using. You may prefer to use a specific browser, but the software you need to see pages comes with that browser, no matter which one you use, whether it be Chrome, Firefox, Explorer, Edge, or Safari. That said, there are softwares that can block specific pages.