Artificial lifeform
An artificial lifeform, artificial organism, synthetic lifeform, or non-biological lifeform, was any sort of automaton that possessed artificial intelligence. Though not all artificial lifeforms had sentience, they often appeared in humanoid form. The terms synth or synthetic were, by the late 24th century, used to describe such life. () 

Cyberneticists and robotics scientists were students of cybernetics and robotics, respectively, and were the key developers of artificial lifeforms. (, et al.)

Appellations 
Examples of such beings included androids, Automated Personnel Units, some holograms, HD25 Isomorphic Projections, and some robots. (; ) Internal sensors aboard Federation starships were capable of identifying artificial lifeforms. ()

The Baneans utilized artificial lifeforms to serve as the host to the memory engrams and testifies to their content. ()

In the Federation, according to B'Elanna Torres, artificial lifeforms "come different shapes, and sizes. Some have limbs, some don't. Most don't have [..] cognitive abilities." She continued, "the robots we use are servants in a manner of speaking. But they aren't sentient," with exception of Data, who she described as "the one sentient artificial lifeform in our society," who "is treated the same as any Human." ()

Androids 
When the Soong-type android, Data, was first activated by the crew of the , he was told that he was "nothing more than a sophisticated machine with Human form." () When Data later inquired as to why he was given Human form, Geordi La Forge theorized that it was "to make it easier for Humans to relate to you," but also, "your designer may have had something else to prove as well." According to Captain Jean-Luc Picard, he felt that that "something else" might have been to prove "that Human-shaped robots need not be clumsy or limited." ()

It was also the belief of Commander Bruce Maddox, the Associate Chair of Robotics at the Daystrom Technological Institute, who later studied Data, that the android was "an extraordinary piece of , but it is a machine." () 

Even Captain Jean-Luc Picard once pointed out, in 2364, that "Data is a machine, just remember that we are merely a different variety of machine. In our case, electrochemical in nature." () 
When Data was first introduced to Malcorian Chancellor Avel Durken, he was described as android, or more simply, "a constructed being." When Durken interpreted that to mean "a machine," Data himself acknowledged "in a manner of speaking," before clarifying that "the term artificial lifeform would be more accurate." () 

During Captain Montgomery Scott's encounter with Lieutenant Commander Data in Ten Forward aboard the USS Enterprise-D in 2369, Scott observed of Data that "you're not quite human, are you?" He later observed, while discussing synthehol with an android, "synthetic scotch, synthetic commanders." ()

Later that year, during Data's encounter with DS9's chief medical officer, Dr. Julian Bashir, Bashir immediately recognized Data as "the synthetic lifeform." Excited by the encounter with a being he had heard so much about, Bashir hoped to discuss Data's perspective on the subject of biocybernetic research. After observing many of Data's physiological traits, Data noted that "most people are interested in my extraordinary abilities. How fast I can compute, my memory capacity, how long I will live. No one has ever asked me if my hair will grow, or noticed that I can breathe." Bashir then pointed out how fascinating he found it that Data's creator "went to a lot of trouble to make you seem Human." ()

By 2371, Data believed that his growth as an artificial lifeform had reached an impasse, describing that, since his activation in 2337, he had endeavored to become more "Human", and grow beyond his original programming, yet, he still was unable to grasp such a basic concept as humor. This led to the incorporation of an emotion chip. ()

In Data's latter attempt to understand the fear of some of the young Ba'ku had towards him, he determined that he was "the personification of everything they have rejected," namely technology in general. Captain Picard continued Data's analysis, pointing out that, "until this week, [many] probably never saw a machine, let alone one that walks and talks." ()

Although many had tried and failed to replicate the work of Noonian Soong, it was not until after the death of Lieutenant Commander Data that this work became advanced enough to work on a large scale. Scientists at the Daystrom Institute's Division of Advanced Synthetic Research, including Bruce Maddox, were able to create the A500, many of which worked as manual labor at Utopia Planitia Fleet Yards on Mars. They were described as having enough strength to tear titanium apart with their bare hands. Although functional and quite capable of carrying out instructions, the A500s had no capability for interacting with people on any meaningful level, leaving some Humans feeling awkward or ill at ease with them. ()

On April 5, 2385, a group of A500s appeared to go rogue and attacked a fleet that was being built to aid in an evacuation effort of Romulus, due to its sun having been predicted to go supernova. The attack itself was carried out by sabotage, as well as a large number of starships, an incident that Starfleet Admiral Jean-Luc Picard described as "devastating" to the Federation News Network shortly thereafter. The attack cost over 92,000 lives, destroyed the Utopia Planitia Ship Yards and ignited gases in the atmosphere of Mars, causing fires which were still burning more than a decade later. The official conclusion placed blame on what was seen as a fatal code error in the A500 operating system. (; )

In response to the attack, the Federation banned the creation of new synthetic beings, dismantled all operating androids and halted all research. Despite this ban however, illicit work was still carried out, resulting in the creation of Dahj and Soji Asha. () The ban was subsequently repealed in 2399, thanks to the efforts of Picard proving that the A500s had been purposely hijacked by an outside force to carry out the attack. ()

Cyborgs 
Though not considered artificial lifeforms themselves, biological lifeforms augmented with artificial implants were not uncommon, and were generally referred to as cybernetic organisms, and included such species as the Borg and the Bynars. (; ; )

Locutus of Borg considered Data to be a "primitive artificial organism" and was told he would be obsolete in the new order. () However, according to Lore, after he encountered a group of "lost" Borg, sometime around 2369, he claimed to have found his calling, on account of the fact that, according to Data, "The Borg aspire to the perfection my brother and I represent. Fully artificial lifeforms. We are their future." Later, Hugh, one of those "lost" Borg, later explained that when they were discovered by Lore, he fed them "the promise of becoming a superior race, of becoming fully artificial," something he found to be "compelling". ()

Exocomps 
During the late 2360s, Doctor Farallon, a Tyran scientist and inventor, designed and created exocomps as engineering tools. 

When Data saw signs of intelligence in the devices in 2369, Dr. Farallon accused him and his colleagues of anthropomorphizing them. When she further compared her work to that of Dr. Noonien Soong's, a man whom she had "nothing but the utmost respect and admiration for," she indicated that while "his intention was to create an artificial lifeform," she "created the exocomps to be tools." She further added that, "there is a big difference between Data and a tool." 

Nevertheless, because of the traits the exocomps began to exhibit, it was determined by Captain Picard that, "if the possibility exists, no matter how slight, that these exocomps are lifeforms, then we must examine that possibility." When Farallon later considered that Data was suggesting that they had "superior intelligence," Data indicated that he did not, merely that "they do have superior experience." 

After they demonstrated reasoning skills and self sacrifice, Farallon eventually concluded, for the time being, that she didn't "exactly know what the exocomps are, but you can be assured that until I do, I won't be treating them as simple tools." ()

Holograms 
By the 31st century, on the Kyrian-Vaskan homeworld, artificial lifeforms were considered "sentient and responsible for their actions," and in addition to androids, included holograms. ()

"Pup"  
In late 2369, during an encounter between the crew of Deep Space 9 and "Pup", Lieutenant Jadzia Dax theorized it to be "some kind of non-biological lifeform we've never seen before", explaining that "it all comes down to how we define "lifeform", but just as biological organisms have evolved in our cultures, mechanical life could have done the same in others." ()

Robots 
Though both considered artificial lifeforms, there was a distinct difference between an android and a robot, a fact that Data often pointed out. ()

External link 

 
Lifeform classifications