In biology, cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
The doctype declaration should be the very first thing in an HTML document, before the <html> tag. The doctype declaration is not an HTML tag; it is an instruction to the web browser about what version of the markup language the page is written in. The doctype declaration refers to a Document Type Definition (DTD).
As of Oracle Database 10 g, the XMLTYPE clause is available for use in a SQL*Loader control file. This clause is of the format XMLTYPE(field name) . It is used to identify XML type tables so that the correct SQL statement can be constructed. Example 8-2 shows how the clause can be used in a SQL*Loader control file.