I've always wondered why some random apostrophe is added in the middle of Hebr'ew wo'rds.
Glottal stop probably (suddenly cutting off the air stream in your throat), either carries meaning and/or just to separate vowels so you don't pronounce "aa" as a long "a", but "a a" or "tt" as two distinct "t t" and not just one "t" with a long rest or something.
Cockney English features them prominently where final consonants are deleted (wha', tha', etc) and most German words begin with one (every word that beings with a vowel actually begins with a glottal stop, for instance). African American English has them too, whenever the indefinite article "an" turns into "a", like "a egg", or "a 'egg", if you will. Dunno which came first though, the deletion or the glottal stop.