An "entity" is a fancy term for a symbol. Some characters are reserved in Html. It is not possible to use the less than (<) or greater than (>) signs in text, because the browser will mix them with tags. Several symbols, such as copyright, trademark, or foreign cash symbols are not exist on standard keyboards. To actually display reserved characters, we must use character entities in the Html source code.
| ||Non-breaking space|
|±||±||Plus or minus|