There are usually two "levels" of your web page that can be marked up with Schema.org (note that I made these levels up for this answer; the difference is not always useful):
- level 1: the web page itself (i.e., the transport medium)
- level 2: the content/entities contained in the web page
Obviously, every web page can be marked up with WebPage (or one of its more specific types). Welcome to level 1. With such markup, you are specifying 1.) that it’s a web page, and, if you use a more specific type, 2.) what kind of web page it is. Note that having this markup is not necessary, and consumers like search engines are often more interested in level 2.
With level 2, you specify what the page is about, and what entities it contains/mentions. This can be everything, starting from Thing.
In your question, you give this example for "general web pages":
These pages contain general information about the company and other information that is not specific articles.
For a page containing "general information about the company", it might be appropriate to use the AboutPage (level 1). And because this page is about a company, it might be appropriate to use Organization (level 2).
Unfortunately, Schema.org still lacks a property to specify that something (Thing) is the main content a page (→ WebPage) is about. If you want to use only one item on your page, use