The iMac, first released in 1998, was Steve Jobs's first major product (and major success) after rejoining Apple in 1996. Though not nearly the first all-in-one desktop computer--the early Apple machines from the early 1980s were stylistic predecessors--new attention was paid to the simplicity and approachability of the iMac. The tagline: "There is no step three!", based on the two-step process required to get the computer connected to the internet, right out of the box.
The idea: this is not a hulking box for programmers. This is a fun computer, all in one neat package, that'll let you do what you want to do as easily as possible.