Partial vowelling

Hebrew spelling (Hebrew: כתיב עברי‎‎ /ktiv ʕivˈri/, "Hebrew spelling") refers to the way words are spelled in the Hebrew language. The Hebrew alphabet contains 22 letters, all of which are primarily consonants. This is because the Hebrew script is an abjad, that is, its letters indicate consonants, not vowels or syllables. An early system to overcome this, still used today, is matres lectionis, where four of these letters, alef, he, waw and yodh also serve as vowel letters. Later, a system of vowel points to indicate vowels (diacritics), called niqqud, was developed.

Throughout history, there have been two main systems of Hebrew spelling. One is vocalized spelling, the other is unvocalized spelling.

In vocalized spelling (ktiv menuqad), all of the vowels are indicated by vowel points (called niqqud). In unvocalized spelling (ktiv hasar niqqud), the vowel points are omitted, but some of them are substituted by additional vowel letters (waw and yodh). This system is the spelling system commonly used in Israel today.

Vowel points are always optional in Hebrew. They can be used fully, partially or not used at all. The recommended approach endorsed today by the Academy of the Hebrew Language and other Israeli educational institutions is to use "plene" spelling (matres lectionis) when not adding vowel dots (which is the usual case), and place a vocalization sign on a letter only when ambiguity cannot be resolved otherwise. The "defective" spelling is recommended for a fully vocalized text, hence its use is becoming rare. Texts older than 50–60 years may be written in an unvocalized 'defective' spelling (for example, the word ħamiším "fifty", was written חמשים on banknotes issued in Mandatory Palestine or the Bank of Israel in its early days. Today, the common spelling is חמישים). A vocalized 'plene' spelling system is common in children books, when it is better to accustom the children to the more popular 'plene' spelling, while still letting them benefit from the vowel dots as a reading aid in early learning stages.

...
Wikipedia