Three consonants carry one idea: gathering things in and holding them. As a verb it is the act of stockpiling; pour the same letters into a noun mould and you get the place that holds the reserve (a reservoir), or the small thing collected and sent (a note). The toll you pay is even the same root: a fee is what gets gathered in. 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.
Only the active pa'al and its passive partner nif'al are lexicalized here: you store, or things get stored. The intensive (pi'el) and causative (hif'il) tracks were never settled for this root, which is normal: most roots fill only two or three of the seven binyanim.
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.