The Koprulu Sector
Blizzard's primer says human colony ships reached the distant sector in 2259. Human political groups formed there, while Terrans later encountered the Protoss and Zerg.
Legacy canon / spoilers marked below
A short StarCraft primer
Blizzard’s story primer covers the earlier campaigns. The old characters and worlds here are background, not confirmed returns.
Three distinct powers
The classic setting follows Terran societies, the Zerg Swarm, and the Protoss. Their conflict and asymmetric identities are long-running StarCraft themes.
Campaign sequence
The major story arcs span StarCraft, Brood War, then StarCraft II: Wings of Liberty, Heart of the Swarm, and Legacy of the Void.
Reference: Blizzard's StarCraft Story Primer ↗.
Major story spoilers from the legacy games
Blizzard's primer recounts the fall of Aiur, the emergence and shifting loyalties of the Terran Dominion, and the later conflict around Amon and the Xel'Naga. These are older campaign events. The new game's plot and returning characters have not been announced.
For the full story and original images, see Blizzard’s primer.
Keep the new game separate
For the new title, Blizzard has confirmed only the public name STARCRAFT, an original open-world shooter, the Koprulu Sector setting, and a Spring 2030 target. Comments on the new game’s story, factions, and timeline come from a developer interview, not the official announcement. They are labeled on the evidence matrix.