How it began:
The formation of the genre had started in the West during the Industrial Revolution with the future of the impact of technology. This had progressed into space, travel, robots, time travel, and etc. Many relate to utopian aspirations and imaginary worlds. Writers appeal to new developments so that the changes will shock the audience. This approach was introduced by H.G. Wells, who had founded SF, and is considered one of the genre's best writers. He had used Charles Darwin's theory of evolution to create satire and utopian factors. The SF genre has a target audience of 18-29 year old males. Males tend to be catered to this genre due to their repetition of protagonists, action, and graphics.
Conventions:
A genre convention are elements in the story, like setting, characters, or tone, that are associated with a certain genre. Science based themes are implemented into the plot of many SF films. Most sci-fi films explore futuristic elements and incorporate advanced technology. The characters involved in science fiction may include aliens, extra-terrestrials, robots, androids, humanoids, a hero, victim, protagonist trying to save the world, antagonist, or sidekick.
Many science fiction films are saga's, a series or long story, these characters play an important role by keeping the audience intrigued through their actions. In sci-fi films, many of the same actors and actresses are used to attract their audiences, as connections are formed to the characters. For example, the Star Wars films include some of the most well-known characters in film history, like Darth Vader, and even Harry Potter, from the Harry Potter series. It is because of these characters that people become so engaged in a film.
A lot of sci-fi films use some sort of VFX work, or special effects. This includes smoke, lasers, flames or fire, snow, confetti, and many other visual conductions. These visual effects can make or break a SF film. The film 2001: A Space Odyssey, produced in 1968, was praised for its visuals and was even nominated and won an Oscar for Best Special Visual Effects. This film used the effect of a floating pen in spaceship that a women grabs out of midair and starts to write with.
Sci-fi films tend to use cooler tones. Because many take place in unsettling environment, these cooler colors tend to create a more uneasy and unsettling feeling, while warmer colors may make the audience feel more comfortable. In science fiction movies, there is a lot of representation by color blue. This is a dominant color as it interfaces with technology, yet to come.
Iconography is also an important factor. This includes high-tech gadgets, like a light saber (used in Star Wars), holographic images, makeup, special effects, weapons, spaceships, teleporting machines, laboratories, and unique customs. Many of these factors become Halloween customs because of their popularity and appeal to the audience. Again, from Star Wars, Darth Vader or even Storm Trooper customs, are still, years after the original release of the films, are one of the most popular children customs. Institutional conventions relates to the marketing and image of a film.
Marketing:
Many sci-fi films use the marketing strategies of the characters in the films. Because many are series, these characters are well-known, and due to the connection created to the characters, using them to market the film can bring in a larger audience. When creating a science fiction saga, if the first film does well, typically, when creating sequels, people will be dragged in. The method of using prominent characters to advertise is extremely useful.
Sample 1:
Gravity (2013)
The film, Gravity (2013), revolves around a veteran astronaut, Matt Kowalski. He is currently in charge of the Shuttle Explorer's STS-157, which is a mission to fix the Hubble Telescope by the newbie specialist, Ryan Stone. Out of nowhere, Houston control releases a warning to the mission that a Russian missile had hit the satellite. This causes a reaction now creating a storm of debris charging the astronauts. Communication is lost between them and the Mission Control in Houston. The debris strikes the Explorer and Stone is released from the shuttle, although, the Explorer is completely destroyed and now the only option to get back to Earth is to get to another space station. Unfortunately, another issue occurs, they are short on oxygen and fuel. The basis of the movie revolving around space travel and advanced technology relates it to science fiction, but, this movie also can be considered a drama and adventure movie.
Sample 2:
Back to the Future (1985)
Back to the Future (1985), is one of the most iconic and well-known films of all time. This film takes place in the year 1985, where the high school student, Marty McFly, had stopped by Dr. Brown's laboratory to mess with an amplifier. He is informed by the Dr. that he needs help for his latest invention, a time machine. This time machine would make travel through time instantaneous, while reaching top speeds of 88 MPH. Marty uses this machine when Dr. Brown is gunned downed and he needs to escape. He travels back to 1955, where he meets both of his parents as teens and interrupts their first encounter. He also comes across the young Doc, and they go on a mission to get his "parents" back together and then go back into modern time. This film utilizes time travel, leading to the science factor and science fiction genre. This was a very popular genre during the time, which could be one of the reasons for the popularity of the film.
Some Science Fiction Films:
Interstellar (2014) 
Avatar (2009)
Dune (2021) 
The Terminator (1984)
The Matrix (1999) 
2001: A Space Odyssey (1968)
