Normally I refrain to talk about Apple II because it was not a computer for the "masses" as we will see. Anyway, Apple II is a very good example of the duo Steve Wozniak & Steve Jobs.
Steve Wozniak designed the Apple ][ and give Apple fuel to "Think different" and then produce the Steve Job's Macintosh.
Apple ][ is the humble system which you need to sell, to do great things.
So let's summarize why Apple ][ is damn important.
The Apple ][ is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak (Steve Jobs oversaw the development of the Apple II's foam-molded plastic case).
Figura 1 Apple ][ Figura 2 Apple ][ +
It was a long-selling product from 1977 to end of 1982 and sustained Apple revenue up to Machintosh success
Timeline of Apple II family models
From Wikipedia, https://en.wikipedia.org/wiki/Timeline_of_the_Apple_II_family