Once upon a time Microsoft, like everyone else, used 7-bit character sets, and they invented their own when it suited them, though they kept ASCII as a core subset. Then they realised the world had moved on to 8-bit encodings and that there were international standards around, such as the ISO-8859 family. In those days, if you wanted to get hold of an international standard and you lived in the US, you bought it from the American National Standards Institute, ANSI, who republished international standards with their own branding and numbers (that's because the US government wants conformance to American standards, not international standards). So Microsoft's copy of ISO-8859 said "ANSI" on the cover. And because Microsoft weren't very used to standards in those days, they didn't realise that ANSI published lots of other standards as well. So they referred to the standards in the ISO-8859 family (and the variants that they invented, because they didn't really understand standards in those days) by the name on the cover, "ANSI", and it found its way into Microsoft user documentation and hence into the user community. That was about 30 years ago, but you still sometimes hear the name today.

ANSI encoding is a slightly generic term used to refer to the standard code page on a system, usually Windows. It is more properly referred to as Windows-1252 on Western/U.S. systems. (It can represent certain other Windows code pages on other systems.) This is essentially an extension of the ASCII character set in that it includes all the ASCII characters with an additional 128 character codes. This difference is due to the fact that "ANSI" encoding is 8-bit rather than 7-bit as ASCII is (ASCII is almost always encoded nowadays as 8-bit bytes with the MSB set to 0). See the article for an explanation of why this encoding is usually referred to as ANSI.

“ANSI”这个名字是不恰当的，因为它不对应任何实际的ANSI标准，但这个名字一直存在。ANSI与UTF-8不同。

ANSI(又名Windows-1252/WinLatin1)是拉丁字母的字符编码，非常类似于ISO-8859-1。 你可以去维基百科上看看。

我记得当“ANSI”文本引用伪VT-100转义码通过ANSI在DOS中可用。SYS驱动程序来改变流文本....可能不是你指的，但如果是，请参阅http://en.wikipedia.org/wiki/ANSI_escape_code

基本上“ANSI”指的是Windows上的遗留代码页。请参阅Raymond Chen关于此主题的文章:

这是因为Windows代码页1252最初是基于ANSI草案，后来成为ISO标准8859-1。

在大多数代码页中，前127个字符与ASCII相同，但上面的字符有所不同。

然而，ANSI并不自动表示CP1252或拉丁1。

尽管有很多困惑，但您现在应该简单地避免这些问题，并使用Unicode。

Once upon a time Microsoft, like everyone else, used 7-bit character sets, and they invented their own when it suited them, though they kept ASCII as a core subset. Then they realised the world had moved on to 8-bit encodings and that there were international standards around, such as the ISO-8859 family. In those days, if you wanted to get hold of an international standard and you lived in the US, you bought it from the American National Standards Institute, ANSI, who republished international standards with their own branding and numbers (that's because the US government wants conformance to American standards, not international standards). So Microsoft's copy of ISO-8859 said "ANSI" on the cover. And because Microsoft weren't very used to standards in those days, they didn't realise that ANSI published lots of other standards as well. So they referred to the standards in the ISO-8859 family (and the variants that they invented, because they didn't really understand standards in those days) by the name on the cover, "ANSI", and it found its way into Microsoft user documentation and hence into the user community. That was about 30 years ago, but you still sometimes hear the name today.