Data is a character from Star Trek - The Next Generation, he is an android designed by Dr. Noonien Soong , on the planet Omicron Theta, and hold the rank of lieutenant commander in star fleet and is the third in command of the Enterprise the federation flagship. Data is played by actor Brent Spiner who also played the part of Dr. Noonien Soong in a number of episodes of the show.
Data is equipped with a positronic brain that allows him to be rational, with an analytical mind but find it difficult to understand human emotions, feelings and behaviors, making him comparable to Vulcans such as Spock.
Data was found on Omicron Theta after the colony had been destroyed by a crystalline entity, after his rescue by the USS Tripoli, Data decided to join Starfleet which he easily graduated.
Data excels in science and the analytical functions, but tend to sometimes have difficulty with interpersonal relationships and has endeavored to understand humanity by following interests in the creative arts such as music, painting and acting.
Data is one of a limited number of Soong type androids, others include his brother Lore, another android of Noonian Soong`s wife Juliana Soong that was created when the real Juliana Soong was killed, B-4 a prototype android created by Noonien Soong, another Soong type android was created by Data called Lal, but unfortunately her positronic brain failed after a few weeks. Brent Spiner played the parts of B-4 and Lore.
Data despite being an android has known to have emotions thanks to the emotion chip he got from his brother Lore. It has taken a lot of work to understand and manage them. He was tempted by the Borg Queen biological implants enabling him to "feel" the sensations of human skin.
In the last film of the saga of Star Trek (Star Trek: Nemesis, 2002) Data sacrifices himself to save the crew of the Enterprise E. However, his homologue and less developed (called B-4 pronounced as "before") receives all the information from data before the fatal outcome. Although in principle B-4 seems unable to take the same personality of the famous android Starfleet, the door for further development of the character remains open, although it is clear that Data has passed away in the plot of the series.
In the miniseries in comics Star Trek: Countdown (the official prequel to the film Star Trek directed by JJ Abrahams in 2009) Data, having successfully transferred their algorithms and positronic memories to B-4, it appears as commander of the Enterprise-E in mission to stop Romulan Nero. Spock compares the "resurrection" of Data with his own death and return years ago.
Have a look at the information on Commander Data the lovable android from Star Trek TNG