It's a class of script. A language with a script that omits vowels is called a "(pure) abjad(ic)" language. Egyptian (arguably, I'm not a linguist) and Arabic are examples of "impure abjad" languages. Usually they have diacritics that hint at vowel sounds but are otherwise devoid of explicit vowel glyphs, so I'm not sure if Egyptian strictly fits that bill - maybe someone else does. Point is, it's perhaps a bit foreign to latin-language speakers but there's a whole class of languages that do this, or something similar.

There are a few purely abjadic languages, one that comes to mind I believe is Phonician.