witty analogy to abstractly explain difference between various linux distros

today my friend came to me asking which linux distro i have with me. i replied. then he asked me whether there shall be any differences between shell operations of various distros. i told him that for learning purposes, all major/current linux distros behave almost identically. then he asked me what exactly is the difference between various distros like ubuntu, red hat, fedora etc. i wondered for a while thinking how to explain this to him, and then spontaneously this analogy came to my mind.

i told him that just like a 'small car' is a thing and like there are various embodiments of it from different vendors- hyundai atos/santro or daewoo matiz or chevrolet spark or hyundai getz or maruti suzuki alto, a linux distribution is an abstract concept, and the various distros by different vendors all are embodiments of it. thus no matter whether it is a hyundai car or a suzuki one, they all will behave identically for learning purposes, and each one of them is both different in numerous little things [depending upon what a particular company's engineers and designers deem appropriate], and yet identical broadly.

my friend both perfectly understood the difference, and appreciated this analogy. i dont know from where this nice analogy came to my mind, and am writing this here because i think this can nicely solve the same query of any other fellow too.