What is Alef Hamza?

I'm a speaker of Arabic, and Alef Hamza is the character Alef "ا", and Hamza "ء" (or Madda "~") is written with it, like "أ", "إ", or "آ".

So that option means if you want to match Alef only, or Alef with something else.

Example, some search engines consider "è, é, ê or ë" as "e", but others consider them other characters.