amazons numbering / naming is a nightmare
wikipedia is best for clearing up confusions
amazon marketing dept will quote generation , and/or years as well as numbers, plus they invent/discard names: e.g. kindle Fire ( dropped), voyage ( no longer in production). HDX ( ditto), Paperwhite, oasis... "Basic" is another moveable label - tends to get applied to whatever is the cheapest one at the time. and don't get me started on their use of " all new"
and often there s no visible difference between generations, so if you are looking to buy used on ebay it can be challenging. e.g. a paperwhite gen 1
looks like a paperwhite gen 3 but has poorer resolution... a 3rd Gen HDX
looks just like a 4th Gen HDX...
this applies to kindles and to tablets- i have twice bought tablet covers that didn't work properly because I muddled my generations , and if you get the gen or year wrong, chances are that auto wake/sleep will not work as they move the magnets around inside the designs.
for kindles, try this
https://en.wikipedia.org/wiki/Amazon_Kindle
and for fire / kindle fire:
https://en.wikipedia.org/wiki/Amazon_Fire_tablet
then you have to match the wiki entries to whatever marketing blurb you find on the for sale listings