UTF-8 bomb is also called UTF-8 signature. In fact, UTF-8 bomb has no effect on UFT-8, but it was added to support UTF- 16 and UTF-32.

BOM, meaning BOM, BOM signature is to tell the editor what coding is used in the current file, which is convenient for the editor to identify, but although the BOM is in the editor,

It will not be displayed in, but it will produce output, just like a blank line.

I usually use UTF-8 without BOM format.