The first run of the console is known as the "Heavy Sixer". This is due to the heft of the console, and that it had six of its switches all located to the right and left of the cartridge slot. These units were manufactured in Sunnyvale, CA throughout 1977. A year later, production was moved to Hong Kong, and the heft of the console became lighter. Later iterations and revisions saw the left and right difficulty switches move to the more traditionally seen rear of the unit.
Later units were renamed/rebranded as the 2600, rather than the VCS title. Especially with the release of the Atari 5200 console. The reason for this is to help show consumers that "the higher number represents a newer, more powerful unit". The 2600 name came from the systems model number. Succeeding units would use the same naming methodology, where the model number was also its name.
The Atari VCS was also sold through Sears Roebuck and Company as the "Sears Video Arcade". These units are identical in every way to the Atari branded units, except that they would have Sears Video Arcade on them, instead of the Atari labeling.
In 1986, Atari re-released the VCS/2600 as the 2600 jr. This unit was a smaller, sleeker design. The unit sold for a low low price of around $50 at the time.
Production of the Atari 2600 line ended approximately in 1989. New games were constantly being released for the unit all the way into the end of production, and beyond. Today, there is an enormous homebrew community that continually produces new titles, or updates old games.