If you're talking about web content,
it is basically the writings
which you will find in a web page.
Well I'm not sure if this is an algebra question but content is defined at dictionary.com as:
1. Usually, contents. A. Something that is contained: The contents of a box.
b. The subjects or topics covered in a book or document.
C. The chapters or other formal divisions of a book or document: A table of contents.
2. Something that is to be expressed through some medium, as speech, writing, or any of various arts: A poetic form adequate to a poetic content.
3. Significance or profundity; meaning: A clever play that lacks content.
4. Substantive information or creative material viewed in contrast to its actual or potential manner of presentation: Publishers, record companies, and other content providers; a flashy Web site, but without much content.
5. That which may be perceived in something: The latent versus the manifest content of a dream.
6. Philosophy, Logic. The sum of the attributes or notions comprised in a given conception; the substance or matter of cognition.
7. Power of containing; holding capacity: The bowl's content is three quarts.
8. Volume, area, or extent; size.
9. The amount contained.
10. Linguistics. The system of meanings or semantic values specific to a language (opposed to expression ).
11. A. Mathematics. The greatest common divisor of all the coefficients of a given polynomial. Compare primitive polynomial.
b. Any abstraction of the concept of length, area, or volume.