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.
HyperText Markup Language (HTML) is a Programming language for creating webpages. Webpages are usually viewed in a web browser. They can include writing, links, pictures, and even sound and video. HTML is used to mark and describe each of these kinds of content so the web browser can show them correctly. HTML can also be used to add meta information to a webpage. Meta information is information about the web page. For example, the name of the person who made it. Meta information is not usually shown by web browsers. Cascading Style Sheets (CSS) and JavaScript can be included in HTML code.