Data is the second-officer aboard the Starship Enterprise, ranking lieutenant-commander. He is a sentient android created by Dr. Noonien Soong, a robotic scientist. Before joining Statfleet Data was discovered deactivated by Starfleet personnel on the planet Omicron Theta two years after the planet had been attacked by the Crystalline Entity, a spaceborne creature which converts life forms into energy for sustenance. After they reactivated him he decided he would join Starfleet, where he would then attend Starfleet Academy for four years, serving on two ships before serving aboard the Enterprise.
Because Data was not programmed to have emotions he has an interesting personality. He is the curious type when it comes to trying to understand human emotions, actions, and humor. He finds it difficult to understand these things and he can't seem to grasp the concept of them. He can seem a bit cold and insensitive as a result, but he tries his best at trying to understand how to deal with these situations by studying up on them or asking questions. Most of which still leave him just as confused as when he started. Data is also unable to use contractions like can't and isn't. Instead he says cannot and is not.
In an attempt to learn more about humans Data would take up extra activities such as painting and poetry. He even took an interest in programming holographic recreational activities involving Sherlock Holmes in an attempt to learn various behaviors so that he might better understand humans. This is met with little success, however, as the personalities he tries to use aren't his own and are immediately put away at the conclusion of their usefulness in that given situation.
As Data is an android he was created to be better than your average human. As such he is intellectually smarter than a human and can quicksolve problems that would take us a while to figure out. His storage capacity is stated as "800 quadrillion bits", or 100 petabytes (88.817842 pebibytes), and his processing speed is stated as "60 trillion operations per second" or 60 teraflops. Even with my lack of computer knowledge I'd say that is a lot, definitely more than the world's best computer used today.
As an android Data is immune to nearly all biological diseases and other weaknesses that can affect humans and other carbon based lifeforms which has often benefited the Enterprise in multiple situations. However, because of this he is vulnerable to technological hazards such as computer viruses, certain levels of energy discharges, ship malfunctions (when connected to the Enterprise main computer for experiments), remote control shutdown devices, and so on. Because he is a mechanical construct, technicians such as Chief Engineer Geordi LaForge, prove to be more appropriate to treat his mechanical or cognitive function failures. Despite all this, however, Data is treated as an equal member of the crew.
Data's physical strength is also beyond any human's as he can effortlessly bend a plasteel rod packing a tensile strength of 40 kilobars with his bare hands (as you can see in the screenshot to the left). His hearing is also incredible as it is more sensitive than a dog's hearing. He is able to easily identify several hundred distinct sounds at once. To us it would sound just like noise. For aesthetics purposes Data will limit it to about ten.
Dr. Noonian Soong is the man who created Data. He was one of the Federation's leading cyberneticists up until he was utterly humiliated when he failed to deliver on his promises of a breakthrough on developing a positronic brain. He then disappeared, ending up on the planet Omicron Theta where he went under an assumed name and continued his research in secret. While there he fell in love with and married a woman named Juliana O'Donnell. Together, they perfected his design and built functional humanoid androids with advanced artificial intelligence. Out of the five androids he had made, each representing an advancement and refinement of the potential for their creations, Dr. Soong made Data, whom he considered to be his most successful attempt. Despite lacking emotions and requiring a learning period, Data had progressed more quickly than he had hoped.
When Omicrom Theta was attacked by the Crystalline Entity Dr. Soong escaped with his fatally injured wife and was assumed dead. In truth, he had survived and continued his research in a new location on Terlina III. Data was then found two years later by Starfleet, deactivated. Although he knew Data had been rescued by them he kept his distance but also kept close watch on him. When the time came he activated a homing signal in Data and had come to him. He had plans to give Data a new chip that would allow Data to experience human emotions, but he did not know Lore (the android made before Data and also Data's brother) had been reactivated and was also summoned to his location via homing beacon.
With the two "sons" together Dr. Soong admitted to Data that he would have preferred he had gone into cybernetics like him and continued his work rather than joining Starfleet. Later Lore kills him out of anger and takes Data's chip for himself. As Dr. Soong lay dying Data says he is unable to grieve for him. However, he assure Data that he will grieve in his own way. He then dies; Data then calling him "Father" for the first time.
When defining friendship Data says, "as I experience certain sensory input patterns my mental pathways become accustomed to them. The inputs eventually are anticipated and even missed when absent." Such things can be said about some of his relationships with others during the series. However I am only going to list the ones I feel are the most significant to Data's character, otherwise this could get long.
Lieutenant-Commander Geordi La Forge I feel is the most significant to Data's character––aside from the fact that the two seem virtually inseparable. In the episode The Next Phase when Geordi and Ensin Ro Laren are presumed dead in an supposed transporter malfunction Data confesses to Lieutenant Worf that he never knew what a friend was until he met Geordi, nor was it really something he had ever thought about. He considers Geordi to be his best friend for the fact that he speaks to him as if he were human and would always treat him as such. He accepted Data for what he was. Also Geordi is the only person Data will call by name rather than rank signifying a bond of trust and respect between them.
I think for Data and Captain Jean-Luc Picard it is more of respect and admiration for each other than anything. Despite being a machine Picard acknowledges Data's sentience and treats him as he would any other member of his crew. He is even willing to risk everything––even his career in Starfleet––to help Data when he's in trouble. Likewise, Data is willing to do the same. One perfect example is in Star Trek Nemesis when Picard was going to sacrifice himself to save the Enterprise from the Reman threat. Instead of Picard destroying the Reman ship from within, Data sends the captain back to the ship sacrificing himself instead.
In all honesty I don't like Q. The guy drives me nuts. However, I still felt he deserved a spot here. In the episode Deja Q when Q is thrown out of the continuum and looses his omnipotence the interaction between him and Data makes me less resenting and more sympathetic to his character. As Data called it, it was an irony that Q had become human because it meant that he had achieved in disgrace everything that Data had aspired to be. After that it just seems to spark an interesting relationship between these two and Data even goes out of his way to help Q whenever he was attacked by one of his enemies. Afterward when Q becomes omnipotent again he gives Data a gift for helping him which allowed him to experience laughter for the first time.
A man or machine?
There has been a constant debate throughout the series as to whether Data is to be considered a machine or his own individual person. Among the crew of the Enterprise everyone considers him a person and an invaluable member of the crew. Among other areas of Starfleet, however, they have their own opinions. The perfect example of this is in the episode The Measure of a Man where Data refuses to let Commander Maddox take him apart in order to examine him so that he may learn how he works, and possibly replicate Data, without any guarantee he would be back to normal afterward.
A debate then begins to determine whether Data is the property of Starfleet or his own person. When Data is declared the property of Starfleet Captain Picard challenges it in an attempt to fight it as he believes Data is his own person. This is shown during the trial when he asks Maddox the question "what makes a sentient being?" His answer is intelligent, self-awareness, and consciousness. Picard then argues those points that Data does indeed posses all three aspects making him very much a sentient being. As a result Data is no longer considered the property of Starfleet and has the freedom to choose whatever he wants for himself.
This episode is also very interesting because it makes the viewers think. As for what I think I've always thought of Data as a person and never really a machine. Though he is far from perfect he is able to function well enough on his own. Because of this this episode always makes me happy when Captain Picard wins.
For the longest time I always though Captain Picard was my favorite character in the series, but after actually sitting down and watching the entire series I discovered that it wasn't entirely true. While he is definitely one of my favorite characters it was Data who intrigued me the most. His aspiration to become more human and his trying to understand things that we simply take for granted––like humor for example––just make me love him all the more. It is amusing on how he would try to imitate various human behaviors like laughing and yawning and look awkward by doing it and how when he's asked to explain something he is always interrupted because if left alone he could probably go on for hours with how specific he is on the details. But what I love the most about Data is he makes you want to try to better yourself, just like how he tries to better himself.