Where does this style work?

It works wherever plain text is accepted — bios, usernames and comments — because the letters are real Unicode characters, not a font.

Can I copy it together with other words?

Yes — copy the whole output and paste it next to plain text; every letter stands alone.

Heavy cursive — logos and signatures

Bold script is the heavy cursive block (𝓑-𝔃) — signature-style text with weight. Popular for logos, names and wedding captions.

𝓨𝓸𝓾𝓻 𝓽𝓮𝔁𝓽 𝓱𝓮𝓻𝓮