单引号里面的字符不会转义。

又引号里面的会转义，变量会被实际的值更改，并且里面的单引号直接输出。

转义列表

`n Newline
`r Carriage return
`t Horizontal tab
`a Alert
`b Backspace
`' Single quote
`" Double quote
`0 Null
`` A single backtick

在执行命令时如果有空格可以用 ` 来替换

We discussed the basic command and pipeline syntax and command parameter
binding.
• PowerShell has four types of commands: cmdlets, functions, script commands,
and native commands, each with slightly different characteristics.
• We discussed the notion of elastic syntax—concise on the command line and
complete in scripts.
• The fact that PowerShell is a command language as well as a scripting language
impacts how it parses text in a number of ways:
• PowerShell parses scripts in two modes: expression mode and command mode,
which is a critical point to appreciate when using PowerShell.
• The PowerShell escape character is backtick (`), not backslash.
• PowerShell supports both double-quotes and single-quotes; variable and expression
expansion is done in double quotes but not in single quotes.
• Line termination is handled specially in PowerShell because it is a command
language.
• PowerShell uses a sophisticated formatting and outputting system to determine
how to render objects without requiring detailed input from the user.