Wipe, in a computing context, means  to render all data on a hard drive unreadable. The term is often used in reference to making data stored on a computer, smartphone or tablet inaccessible before disposing of the device.
A semantic HTML tag is one that defines a meaning to the enclosed content that a computer can be programmed to understand. In most cases, browsers create some visual difference to content in semantic tags, for example, content in the CODE element is usually displayed in a monospaced font. But this is not a requirement. Many people feel that semantic HTML elements are a waste of bandwidth.
HTML5 has redefined the meaning of the <b> and <i> tags to be semantic. The <b> tag doesn't convey extra importance, but rather text that is typically rendered in bold. The <i> tag also doesn't convey extra importance or emphasis, but rather defines text that is typically rendered in italics. Semantic HTML Tags.