Game Boy line

The Game Boys are a group of handheld video game consoles made by Nintendo that ran from 1989 to 2009.
Game Boy
The first Game Boy was released in 1989. It had a small screen, a D-pad, Start and Select keys, and an A and B button. To play games, there were small objects called cartridges that you put into the Game Boy to play the game in the cartridge. The game that made it popular, and the system's launch title, was Tetris. The Game Boy had a link cable and a link port which let it connect with other Game Boys to play games in multiplayer mode.
Game Boy Pocket
After the Game Boy, Nintendo released the Game Boy Pocket, which was a smaller Game Boy more convenient to carry around. It had a better, sharper screen and it only needed two AAA batteries instead of four AA. The link port was smaller than the Game Boy's, so the Game Boy and Game Boy Pocket could not connect with the original connector cable; a newer model cable with double-sided ends was needed to do this.
Game Boy Light
The Game Boy Light was only released in Japan and had a front-light (the blue light used on old watches) so people could see better. It is very rare - only about 12,000 of them were manufactured. Because it is rare, it sells for more money than other Game Boys.
Game Boy Color
The Game Boy Color was the first Game Boy in color. It was also able to play Game Boy cartridges, which helped it sell better. This also helped other Game Boy models after the Game Boy Color. It is sometimes called the GBC.
Game Boy Advance
The Game Boy Advance is a handheld that had better color and smaller cartridges. It could play more advanced games than the previous Game Boys. It is sometimes called the GBA. It came out in March 2001.
Game Boy Advance SP
The Game Boy Advance SP was an improved version of the original GBA. It has a clamshell design, which means you can fold it to make it smaller when you're not using it. It has a front-lit screen (better than the one on the Game Boy Light), which the Game Boy Advance did not have. It can play Game Boy and Game Boy Color games, along with the new cartridges introduced with the GBA. A newer model, labeled the AGS-101, was released which had an even better backlight and very good contrast; some people say it is the best way to play Game Boy, Game Boy Color and Game Boy Advance games.
Game Boy Micro
The Game Boy Micro is a smaller variation of the GBA. It has a smaller link port than the Game Boy Advance. Its backlight and contrast are as good as the 101 model of the Game Boy Advance SP. Unlike its predecessors, it cannot play GB or GBC games.
Succesors
The Nintendo DS line is the successor to the Game Boy line. It consists of the Nintendo DS and the Nintendo 3DS.
Nintendo DS
When Nintendo released the Nintendo DS handheld in 2004, they said it was a "third pillar" (the other two pillars were the Game Boy and the home console). It has two screens, one of which is a touch screen. DS games use cards in Slot 1. Slot 2 can accept Game Boy Advance games. A newer model, called the DS Lite, released in 2006, also plays GBA games. But like the GBA Micro, neither of them can play original Game Boy or Game Boy Color games. The DSi and DSi XL, released in 2008 and 2009, replaced the GBA slot with an SD Card. This makes it impossible to play GBA games. Some DS games also included extra features contained in "option paks", which were just like GBA games. So these features could not be used on those DS games if they were played on the DSi or DSi XL.
Nintendo 3DS
Like the DSi and DSi XL, the 3DS line lacks a GBA slot. However, GB and GBC games can be downloaded through the Virtual Console. Those who bought a 3DS prior to the 2011 price drop were lucky to download ten GBA games, along with ten NES games, through the Ambassador Program. While the NES games became available to the public, the GBA games remain exclusive to the Ambassadors.