When to use xargs when piping?

Question

I am new to bash and I am trying to understand the use of xargs, which is still not clear for me. For example:

history | grep ls

H

Answer 1

xargs(1) is dangerous (broken, exploitable, etc.) when reading non-NUL-delimited input.

If you're working with filenames, use find's -exec [command] {} + instead. If you can get NUL-delimited output, use xargs -0.