What does the common word lists mean?

in the most common 100 list there were around 260 sentences but many of them had the same sentences… its easy to know the base for this list as its 0-100 but for other lists like 1000 and 3000
what do they represent actually like does 1000 means 500-1000 words and therefore its 500 words while 3000 means 1000-3000 so its around 2000 words?
please let me know as I wont probably have the time to go through every single sentence so I want to know the best way to use them.

Bear in mind that a word can be a verb, an article, not only a noun. So you will encounter many words, for instance, one of the most common verbs is ‘‘to be’’. You’ll see this verb even in 20000 most common words list. Another thing to mention is that in one sentence you can learn more than just the cloze-word.