One movement runs through this root: arriving, crossing a threshold from outside to inside. In the pa'al you come; flip it causative and you bring (you make something come). The nouns are all about the threshold itself: the entrance, the way in, and by extension the introduction that lets a reader enter a book. Because ב־ו־א has a vav in the middle (a hollow root), its forms look short and irregular, but the idea never wavers. Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
Hollow roots like ב־ו־א rarely fill all seven binyanim. Here the language keeps the pair that matters: the plain motion (to come) and its causative (to bring). The passive and reflexive shells exist abstractly but are not lexicalized for this root.
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.