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.
It is constructed in a similar way: 1  a start tag (<tag>) marking the beginning of an element, which may incorporate any number of HTML attributes; 2  some amount of content, including text and other elements; 3  an end tag, in which the element name is prefixed with a slash: </tag>.