UTF-8 is one way to encode Unicode code points. There's also UTF-16LE, UTF16-BE, UTF-32LE, UTF-32BE, and others like UTF-7. This makes pypy use UTF-8 internal

UTF-8 is one way to encode Unicode code points. There's also UTF-16LE, UTF16-BE, UTF-32LE, UTF-32BE, and others like UTF-7. This makes pypy use UTF-8 internally for the additional memory and speed savings, at the cost of some time later on when you use certain features that require the string index to be built.