In parenthesis now is a tilde which is shorthand notation for My Home Directory.

在圆括号里的,代表根目录。

哈佛公开课 - 计算机科学课程节选

When you type LS it just lists what's in your current folder, my current folder or my so-called home directory.

当你输入LS时，它会把你当前目录下的文件罗列出来，当前目录或者根目录。

哈佛公开课 - 计算机科学课程节选