Meaning of the word "who is that" in English

What does "who is that" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

who is that

US /huː ɪz ðæt/
UK /huː ɪz ðæt/

Phrase

used to ask about the identity of a person, especially one who is not immediately recognizable or is at a distance

Example:
I saw someone standing by the window. Who is that?
There's a new person in the office. Who is that?