Code Points
A code point is the assignment of a unique number to a character or symbol within a defined code space, so that this character or symbol can be clearly identified and classified. The best known and most widely used codepoint system is Unicode.
Unicode Code Points
Unicode is the Unicode Consortium's attempt to assign a unique numerical value to every common character of every common alphabet in the world, as well as every common symbol, including emoji. There are also a lot of punctuation marks and some non-printable control characters.
This project was started at the end of the 1980s. In October 1991, a first version was finally officially published, which contained 7,129 characters from 24 writing systems. Subsequently, more and more characters were added in regular updates and now over 150,000 different characters and symbols from over 170 writing systems as well as all sorts of other areas from pictograms to smileys have been defined. For example, there are now Unicode codepoints for Egyptian hieroglyphs, Roman numerals, geometric elements and mathematical symbols as well as for chess pieces or playing card symbols (spades, hearts, clubs and diamonds).
Old Codepoint Systems
Before the invention of the Unicode code point system, there had been many other attempts to assign characters to unique numerical values and thus be able to store them and process them automatically.
Partly because of the precious storage space at the time, the initial systems relied on one-byte systems, which could therefore only store 256 different characters (1 byte consists of 8 bits, so there are 2 to the power of 8 = 256 different combinations of these bits).
Countless of these systems were then developed for a wide variety of purposes and alphabets with very different character coverage: Some contained only Latin letters, others Latin and Cyrillic characters or the specific umlauts, diacritics and currency symbols of certain regions and languages, others only contained Greek letters or mathematical symbols - but each only contained a maximum of 256 different characters. So you had to know which code page it was in order to be able to correctly interpret the individual bytes and translate them into characters, and you quickly reached your limits when it came to wanting to save characters that were not part of the selected or available quota. It became particularly difficult when several languages with completely opposite characters had to appear within one text or file.