One of the unique features of Arabic is that all words have a root. for example all the words عالم، معلم، تعلیم، اعلام، علامه all share the same root of ع-ل-م.
In this example our root has only three letters
And then additional letters are added to it to make new words. In Arabic Most of the words you will come accross have three-letter roots حمد – سجد – عبد – خرج – خلق . But there are some four-letter and five-letter roots too.
Four letter root: ج-ع-ف-ر and د-ح-ر-ج
Five letter root: س-ف-ر-ج-ل