As you all know the ASCII chart needed to be extended from 127 encoding to 256, I can't really see why. Some google expert on Coursera said "We needed that because of the foreign languages". I still Can't understand what that has to do with the ASCII Chart.
Can anyone explain the full story?
ASCII has 128 characters. Many countries had similar encodings for 128 characters. That is all history. Nobody uses ASCII anymore. There was a phase with lots of different encodings for more than 128 characters, some with 256 (Mac Roman and Windows 1152 were quite popular) and some like the Chinese GB with thousands of characters.
Nowadays people mostly use Unicode, with a bit over a million code points, which can be further combined to produce more characters. There are plenty of unused code points which can be assigned values in the future, and that happens all the time.
Please note that for most people English is a foreign language. And it would be “naïve” to think that ASCII let’s you write all English text.
There are a few other good reasons to expand from 7-bit ASCII, but since you ask specifically about foreign languages, I want to tell you about that angle.
English has words with diacritical marks, usually loan words like naïve or café. They are rare, and usually you'll get into no trouble for omitting the diacritics. Occasionally one might stumble into a word that means something else when you omit the diacritical marks, such as exposé vs expose, but those cases are rare and usually the meaning can be inferred from the context without much difficulty.
The same is not true for most languages written on the Latin alphabet, though. Romance languages like Italian, French, Spanish and Romanian use diacritics much more than English does, and omitting the diacritics as 7-bit ASCII would impose would make text harder to read. The same is true for Germanic languages other than English, as many of those make heavy use of umlauts and special letters like the å found in Swedish. My native Finnish, too, considers ä, ö and å to be separate characters distinct from a and o, and telling them apart from each other is necessary to correctly parse words without needing to infer from context.
Therefore, when computing picked up pace among users who do not use English as their native language, it was essentially inevitable that the character sets should be expanded. The alternative would have been massive orthographic reforms in some of the most spoken languages in the world to make them conform to the limitations of the increasingly vital computers. That would not have worked out – although semi-official conventions did occasionally spring up (eg. replacing ö with oe). So in order to not get in the way, 8-bit Extended ASCII encodings usually lend support to these special characters, relieving at least some of the non-English languages.
Fast-forwarding to today, Unicode has support for a vast array of characters that extend the support well beyond Latin-based alphabets as well. This means almost everyone can type their native languages without the computer's charset limitations needing to get in the way.
The question of how foreign languages justifies expanding the encoding in actual usage is well explained by earlier answers. The question of why foreign languages would affect the American Standard Code for Information Interchange is subtly different.
As you all know the ASCII chart needed to be extended from 127 encoding to 256
No. The original American Standard Code for Information Interchange (ASCII) has never been extended to 8-bit. It remains to this day a 7-bit encoding standard. The latest revision to the ASCII standard was in 2017, with (ANSI) INCITS 4-1986[R2017].
Due to the same needs for exchanging computer information, non-English speaking countries have to develop their own standard codes. The countries using Latin scripts were already using ASCII in their computers and existing documents. When the 8-bit word architecture became popular, they developed their own standard codes based on the 7-bit ASCII, using the additional bit-space for additional symbols they need. By habit, these standards are sometimes called "extended ASCII" standards. But they are actually new standards, and to this day remain distinct from ASCII. They are standardized as ECMA-94, ECMA-113, ECMA-114, ECMA-118, ECMA-121, ECMA-128, and ECMA-144, as well as the ISO/IEC 8859 series.
