Warning: This article contains SPOILERS for Spider-Man: Far From Home.
The introduction of S.W.O.R.D. in the Marvel Cinematic Universe has subtly happened with Nick Fury at the end of Spider-Man: Far From Home. Although the main plot of the movie is relatively grounded - revolving around Spider-Man (Tom Holland) trying to save the world from Mysterio's (Jake Gyllenhaal) true intentions - Spider-Man: Far From Home's post-credits scene turns its attention towards the cosmic side of the MCU.
Nick Fury (Samuel L. Jackson) is the one responsible for this shift, as the post-credit scene reveals he's in space despite being part of Spider-Man: Far From Home's main plot. In the movie, Fury hijacks Peter Parker's summer vacation so that he can be a superhero the world needs him to be. Peter does his superhero duties reluctantly to help out a legendary figure like Fury, who he officially meets here for the first time (despite seeing each other at Avengers: Endgame's funeral). However, it turns out that Peter has still yet to meet the real Fury as the one he has been in contact with is actually a Skrull - more specifically, Talos (Ben Mendelsohn) from Captain Marvel.
Talos is only posing as Fury so that the real version of the former director of S.H.I.E.L.D. can begin starting his brand new secret organization. He's shown in space and in command of Skrulls, who are all aboard a base of some kind that is still being built. Although the movie doesn't directly say what the new base or organization is called, comic fans will quickly realize the set up that is taking place. It appears that Fury and the Skrulls are constructing the base of operations for S.W.O.R.D.
S.W.O.R.D., or Sentient World Observation and Response Department, is essentially the cosmic side of Marvel's version of S.H.I.E.L.D. Instead of focusing on what is happening on Earth, S.W.O.R.D. is more concerned with what intergalactic threats could pose a threat to the planet. The comic version of the organization was created by The Avengers director Joss Whedon in 2000, when he was writing Marvel comics, and has continued to be a prominent piece of major event stories since then. The structure that Fury and the Skrulls are in and still constructing is likely the Peak, which has served as the central S.W.O.R.D. headquarters for years.
The introduction of S.W.O.R.D. in the MCU makes sense for where the franchise is going. Spider-Man: Far From Home may have further helped set up how a Secret Invasion storyline could be adapted on the big screen, while cosmic series like Guardians of the Galaxy continuing along new films, like The Eternals. A broader focus on the cosmos will then allow S.W.O.R.D. to be the connecting point between the various franchises and characters, with the Peak serving as a possible hub for cosmic characters in-between missions. With Fury being responsible for the launch, it won't be surprising if Captain Marvel takes on a central role with S.W.O.R.D., possibly even by sending them tips on issues around the galaxy that could use a superhero to intervene.
With S.W.O.R.D. and the Peak, though, it also can serve as a bridge between the Earth and cosmic sides of the MCU. Just in Spider-Man: Far From Home it is made clear that Fury is looking towards the stars but hasn't lost complete focus on what happens on Earth. Even if he is eventually replaced as the head of S.W.O.R.D. by someone like Abigail Brand, a mutant/alien hybrid who serves that role in the comics, the purpose of the organization is still to protect Earth. So, if another mega-level cosmic threat heads to Earth in the next decade, S.W.O.R.D. should be the first line of defense but also can recruit some other Earth-based heroes if need be.