In early 1939, the success of Superman in Action Comics prompted editors at National Comics Publications (the future DC Comics) to request more superheroes for its titles. In response, Bob Kane created "the Bat-Man". Collaborator Bill Finger recalled that "Kane had an idea for a character called 'Batman,' and he'd like me to see the drawings. I went over to Kane's, and he had drawn a character who looked very much like Superman with kind of ... reddish tights, I believe, with boots ... no gloves, no gauntlets ... with a small domino mask, swinging on a rope. He had two stiff wings that were sticking out, looking like bat wings. And under it was a big sign ... BATMAN". The bat-wing-like cape was suggested by Bob Kane, inspired as a child by Leonardo Da Vinci's sketch of an ornithopter flying device.
1994's company-wide crossover Zero Hour changes aspects of DC continuity again, including those of Batman. Noteworthy among these changes is that the general populace and the criminal element now considers Batman an urban legend rather than a known force. Similarly, the Waynes' killer is never caught or identified, effectively removing Joe Chill from the new continuity, rendering stories such as "Year Two" non-canon.
Peak Human Conditioning: Through intense training, specialized diet, and biofeedback treatments, The Batman represented the absolute pinnacle of human physical prowess. His physical attributes is at the natural limits far above than that of an Olympic level athlete that has ever competed. His strength, speed, stamina, agility, reflexes, senses, healing and endurance are at the peak of human potential. Batman began his physical and mental conditioning when he was 10 and then intense physical training and weight lifting at age 12. He had mastered full body control by the time he was 18. Bruce Wayne, since the age of 15, has created a strict diet to enable his body to develop and operate at its most proficient, along with biofeedback treatments (using portable/non-portable machines to stimulate muscles to contraction). Batman being able to perform amazing physical feats is due to his superior physique. He engaged in an intensive regular regimen of rigorous exercise (including aerobics, weight lifting, gymnastics, and simulated combat) to keep himself in peak condition, and has often defeated opponents whose size, strength, or other powers greatly exceeded his own. He has spent his entire life in pursuit of physical perfection and has attained it through constant intensive training and determination. Following his recent exposure to Dionesium he has become much stronger and faster than ever before.
Batman meets and regularly works with other heroes during the Silver Age, most notably Superman, whom he began regularly working alongside in a series of team-ups in World's Finest Comics, starting in 1954 and continuing through the series' cancellation in 1986. Batman and Superman are usually depicted as close friends. Batman becomes a founding member of the Justice League of America, appearing in its first story in 1960s Brave and the Bold #28. In the 1970s and 1980s, Brave and the Bold became a Batman title, in which Batman teams up with a different DC Universe superhero each month.
DC's 2005 limited series Identity Crisis, reveals that JLA member Zatanna had edited Batman's memories, leading to his deep loss of trust in the rest of the superhero community. Batman later creates the Brother I satellite surveillance system to watch over the other heroes. Its eventual co-opting by Maxwell Lord is one of the main events that leads o the Infinite Crisis miniseries, which again restructures DC continuity.
Various modern stories have portrayed the extravagant, playboy image of Bruce Wayne as a facade. This is in contrast to the post-Crisis Superman, whose Clark Kent persona is the true identity, while the Superman persona is the facade. In Batman Unmasked, a television documentary about the psychology of the character, behavioral scientist Benjamin Karney notes that Batman's personality is driven by Bruce Wayne's inherent humanity; that "Batman, for all its benefits and for all of the time Bruce Wayne devotes to it, is ultimately a tool for Bruce Wayne's efforts to make the world better". Bruce Waynes principles include the desire to prevent future harm and a vow not to kill. Bruce Wayne believes that our actions define us, we fail for a reason and anything is possible.
As a member of the Flying Graysons acrobatic family, young Dick Grayson thrilled audiences nightly on the high wire beside his circus aerialist parents. But when gangster "Boss" Zucco sabotaged the high wire because the owner of Haly's Circus refused to offer up protection money, the elder Graysons paid with their lives. Billionaire Bruce Wayne was in the audience that night; however, it was Batman who visited the grieving Dick Grayson, offering the boy a chance at retribution by becoming Robin, the Dark Knight's squire in his personal war on crime.
Following the 2016 DC Rebirth continuity reboot, Batman and Catwoman work together in the third volume of Batman. The two also have a romantic relationship, in which they are shown having a sexual encounter on a rooftop and sleeping together. Bruce proposes to Selina in Batman vol. 3, #24 (2017), and in issue #32, Selina asks Bruce to propose to her again. When he does so, she says, "Yes." 
Many fans of Batman seem to like this design from Frank Miller with it's simple gray and black color scheme, short ears, and bulky utility belt. It was worn by a Batman from a future time where he and many other staple DC heroes had gone into retirement. Of course Bruce Wayne had the hardest time with this. Wayne's reasons for waging a war on crime didn't come from a Boy Scout inspired directive to good. The motivations of Bruce Wayne were personal; it was his way of avenging the death of his parents at the hands of street criminals. At age 55, Wayne comes out of retirement to fight crime in a world that doesn't have the respect for him it once did.
Lucius Fox, a technology specialist and Bruce Wayne's business manager who is well aware of his employer's clandestine vigilante activities; Dr. Leslie Thompkins, a family friend who like Alfred became a surrogate parental figure to Bruce Wayne after the deaths of his parents, and is also aware of his secret identity; Vicki Vale, an investigative journalist who often reports on Batman's activities for the Gotham Gazette; Ace the Bat-Hound, Batman's canine partner who was mainly active in the 1950s and 1960s; and Bat-Mite, an extra-dimensional imp mostly active in the 1960s who idolizes Batman.
@Krunchyman - You do have a very good point. Also, add on the fact that Batman lost both of his parents at a very young age, and it affected him greatly. Parent or not, I'm sure that there are a lot of people who have lost someone very close to them, and that makes them able to relate to Bruce Wayne's tragedy. Going off of what you said about Superman, has he ever lost someone that was close to him? No, I don't think so.
Bruce Wayne goes on a date with Selina, who is unaware of the former's identity as Batman, much to the encouragement of his family. The two, along with Thomas Elliot, attend an opera when Harley Quinn arrives and attempts to kill Bruce. In the ensuing struggle, Dr. Elliot is apparently shot dead by Joker. An enraged Batman violently beats Joker who claims that he is innocent, and he is stopped short of killing him by Commissioner James Gordon. Bruce attends Elliot's funeral and deduces Joker's innocence as well that Hush must know his secret identity.
He then decided to form an international group of Bat-operatives called Batman Incorporated. While he was busy setting this up, he let Dick Grayson (who had taken over when he thought Bruce was dead) remain as Batman in Gotham City. He also got a new costume to differentiate himself from Dick's costume. It had a lot of piping and a protruding, glowing yellow oval; future artists tended to tone down almost all of its elements.
Harley Quinn: Best known as "The Joker's Girlfriend", Harley has had occasional romantic encounters with Batman, most notably her kiss with him in the episode Harley's Holiday from Batman: The Animated Series. Recently, in the The New 52, there have been a couple of stories in which Harley became infatuated either with Bruce Wayne or Batman. These attractions appear to be entirely one-sided and Batman has shown no signs of attraction towards Harley.