" Micro" means very small, and in the case of Twitter, you are essentially blogging something up to 140 characters – that's 140 letters, numbers, symbols, and spaces.

“微” 意味着非常小， 在 Twitter 的情况下，您实际上是在写最多 140 个字符的博客——即 140 个字母、数字、符号和空格。