what are html character entities are used for
List of XML and HTML character entity references The HTML 4 DTDs define 252 named entities, references to which act as mnemonic aliases for certain Unicode characters. The HTML 4 specification requires the use of the standard DTDs and does not allow users to define additional entities.
Bracket Forms include round (also called "parentheses"), square, curly (also called "braces"), and angle brackets (also called "chevrons"); and various other pairs of symbols.
Computer data storage Data are encoded by assigning a bit pattern to each character, digit, or multimedia object. Many standards exist for encoding (e.g., character encodings like ASCII, image encodings like JPEG, video encodings like MPEG-4).
UTF-8 It was designed for backward compatibility with ASCII. Code points with lower numerical values, which tend to occur more frequently, are encoded using fewer bytes. The first 128 characters of Unicode, which correspond one-to-one with ASCII, are encoded using a single octet with the same binary value as ASCII, so that valid ASCII text is valid UTF-8-encoded Unicode as well. Since ASCII bytes do not occur when encoding non-ASCII code points into UTF-8, UTF-8 is safe to use within most programming and document languages that interpret certain ASCII characters in a special way, such as "/" in filenames, "\" in escape sequences, and "%" in printf.