ByteString is a UTF-8 String that corresponds to the set of all possible sequences of bytes. ByteString maps to a String when returned in JavaScript; generally, it's only used when interfacing with protocols that use bytes and strings interchangably, such as HTTP.
As web applications become more and more powerful, adding features such as audio and video manipulation, access to raw data using WebSockets, and so forth, it has become clear that there are times when it would be helpful for JavaScript code to be able to quickly and easily manipulate raw binary data. In the past, this had to be simulated by treating the raw data as a string and using the charCodeAt() method to read the bytes from the data buffer.
USVString corresponds to the set of all possible sequences of unicode scalar values. USVString maps to a String when returned in JavaScript; it's generally only used for APIs that perform text processing and need a string of unicode scalar values to operate on.
The anchor() method creates an <a> HTML anchor element that is used as a hypertext target.
The big() method creates a <big> HTML element that causes a string to be displayed in a big font.
The blink() method creates a <blink> HTML element that causes a string to blink.
The bold() method creates a <b> HTML element that causes a string to be displayed as bold.
The fixed() method creates a <tt> HTML element that causes a string to be displayed in fixed-pitch font.
The fontcolor() method creates a <font> HTML element that causes a string to be displayed in the specified font color.
The fontsize() method creates a <font> HTML element that causes a string to be displayed in the specified font size.
The italics() method creates an <i> HTML element that causes a string to be italic.
The link() method creates a string representing the code for an <a> HTML element to be used as a hypertext link to another URL.
The small() method creates a <small> HTML element that causes a string to be displayed in a small font.
The strike() method creates a <strike> HTML element that causes a string to be displayed as struck-out text.
The sub() method creates a <sub> HTML element that causes a string to be displayed as subscript.
The sup() method creates a <sup> HTML element that causes a string to be displayed as superscript.