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.
Short for HyperText Markup Language, the authoring language used to create documents on the World Wide Web. HTML is similar to SGML, although it is not a strict subset. HTML defines the structure and layout of a Web document by using a variety of tags and attributes.