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.
The <img> tag defines an image in an HTML page. The <img> tag has two required attributes: src and alt. Note: Images are not technically inserted into an HTML page, images are linked to HTML pages. The <img> tag creates a holding space for the referenced image. Tip: To link an image to another document, simply nest the <img> tag inside <a> tags. The following attributes: align, border, hspace, and vspace are not supported in HTML5. In HTML the <img> tag has no end tag.