Blade Runner is an influential and important work of science fiction cinema, one that has spanned decades from release and continues to influence future cinema. So it's no surprise that it inspired a whole new genre of film - the prequel.
Blade Runner 2049 is a sequel to the original 1982 film and so a prequel to the series. It follows in the footsteps of other sequels that have been made - The Thing, Total Recall, The Fifth Element - by following their star characters and taking them into the future.
In the case of Blade Runner, the characters are some of the most famous people of the future, from the replicants (replicas) who exist purely to perform an ethical task and have no feelings of any kind, to the protagonists, the human characters who live on the US/Mexico border, hunted down by a paramilitary force called the U.S.Avenger and forced to go into hiding. The main protagonist, Rick Deckard, is now a Blade Runner himself, at least until he gets released from a work camp.
Blade Runner 2049 is a direct continuation of the first film, taking the characters to the very end of the future, where they're hunted by the other world's equivalent of the bounty hunters from the original film. In this film, they're equipped with body armour and helmets to protect themselves from other applicants and hi-tech weaponry to stop them from killing humans. One thing the new film doesn't have is the awesome score of the original.
Since this is a sequel, it is going to be slightly different from the first film in some ways, especially its story. But it is still the same dystopian future, with heavy emphasis on human augmentation and exoskeletons. It just feels different, especially when it comes to the visuals.
In this film, everything is mechanical and mannequins look like the pieces of a machine (and sometimes they do). There is also a lot of focus on the urban environment of Los Angeles, which makes the film feel more futuristic.
Another popular plot point is whether the relationship between the character Rachael (Olivia Cooke) and Deckard, which were played wonderfully by Jared Leto, will end in romance or in violence. If anything, it is perhaps more romantic than violence that is involved, as in the original film, Deckard is killed off after he kisses Rachael.
A good thing about this film is that we see several scenes, from the prologue through to the ending montage scene, and then never have to watch it again. The length of the film means that you can always stop watching and replay scenes if you want to or just do other things.