Add or remove nikud

Hebrew's alphabet is entirely consonants. Vowels are supplied by the reader, the way an English reader silently fills in "Wshngtn" as Washington from context. That works for a fluent reader on familiar text, so newspapers, novels, street signs and text messages are printed without nikud.

Nikud, the system of dots and dashes added around and inside letters, was developed by the Masoretes around the 7th to 10th centuries CE to fix the exact reading of the Hebrew Bible once it was no longer everyone's spoken language. It stuck for the Bible, the prayer book, poetry, dictionaries and anything written for children or new readers, and dropped everywhere else.