This is a geminate root: the same letter ר repeats, so the consonants are really ק־ר־(ר). One idea runs through every word: cold. As a bare adjective it is the temperature you feel; as a noun it is coldness itself; poured into a verb mould it becomes the act of cooling; and as a tool-noun it becomes the machine that makes things cold, the fridge. Each 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.
Geminate roots like this one mostly live in pi'el for the active verb (cool something) and in the bare adjective/noun. The pa'al "to be cold" is expressed adjectivally with קַר rather than as a finished verb, and the passive/causative binyanim are not lexicalized here. The cooling-down event itself surfaces as the noun הִתְקָרְרוּת.
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.