Length values come in two varieties:
- Relative lengths, which vary depending on the computer being used.
- Absolute values, which remain constant regardless of the hardware and software being used.
Relative lengths values:
- em: Em dash
- ex: x-height
- px: pixel
Absolute length values:
- pt: Point
- pc: Picas
- mm: millimeters
- cm: centimeters
- in: Inches
Color can be written in different way,
- rgb(R#, G#, B#)
- rgb(R%, G%, B%)
The behavior of percentage value depends on the property being used.
A uniform resource locator (URL) is the unique address of something on the Web. URL can be written so that it cancel itself
In some situation placing any URL in the href will interfer with the DHTML functions so the latter code will be used instead. These function simply tells the link to do absolutely nothing.